Saves reverting to points before quitting game, certain chunks refusing to save after quitting world

The last two pictures are showing the items coming back from before. When I reentered the world to find it messed up (avoiding the word corrupted), they were on the ground. I took screenshots... looking over this again, I believe they were duplicated once upon reentering the world. Really they existed in my inventory and in entity form on the ground. I never made more than one of each command block (They are all different and specific, non-stackable, only stackable to an exact match) 

It happened a third time... Providing another screenshot. Once with two items before picking the new clones up, and one after.

Just got it to work a fourth time it is repeatable.

Doing a test now to see if it is a chunk thing.. I put two blazes in two adjacent chunks. If I see two in the same spot, I'll see the duplication.

I've come to a breakthrough... I just quit the game from the chunks pic... joined back in... and the command block items spawned back for a 4th time, and the blazes that were in the same chunk are gone. This means that is TRULY DOES REVERT BACK TO A PREVIOUS POINT. And it only happened in that chunk... sorry I'm excited that I finally understand this soul crushing bug a little bit better. As you can see the blazes in the adjacent chunk are untouched and fine.

Yep. The entire chunk fails to be updated when "Saving and quitting". Blocks are affected as well. I finally have sufficient proof! Sorry I'm just so happy. Worth noting this also happened in another nearby chunk (3 over one back), but I did not test it like I did this one. Should be the same result though.

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Could I just make the attachment of the world available to staff members? That would be preferred. I also don't want to make the whole post private, mainly because the last time I did that, the issue stopped being looked at.

But yes, I can include the world save

I am also adding screenshots better showing the bug. I took them yesterday.

You can make a comment that can be seen only by other users on the bug tracker, but that's about as secure as you can get. The comment won't be seen by users that aren't logged in. Click the lock and arrow next to "Viewable by All Users" and click on "Users" under "Project Roles".

If you can however tell me that the world file definitely does not contain private/personal information, I'd be fine with including the world file. 

It is alright; I'll include it. But it still would be nice to know if it includes anything I wouldn't want others seeing.

**It's in now

And by the way, I did basically report this bug already. I just did not understand it or really know why it was happening. But now I do know how it works, what exactly is happening, at least to what the bug does. However, I am concerned that this will happen again. Last time it happened in my main redstone/commands testing world (now I don't use it for that reason), and now my new Items/Command Concepts world is doing the same thing, but is not fixing itself. I can see that it wasn't just some freak thing. I now definitely cannot use the new commands world, as it is unstable and does not allow me update anything in some surrounding chunks where my commands are.

How do I know this won't happen for a third time?

Just to make sure what exactly should I be observing? What are some ways I can reproduce this issue? Anything helps.

Also your world save folder looks completely fine, I haven't found anything personal included in it.

Alright well thank you for letting me know... anyway as the world is right now it is very simple to recreate, at least on my end (not sure how it will work on your system). First I'd just open the world and see what you have. Then I can know how it looks at the moment for you.

I'll open mine as well so we can both do the same things

Let me know when you have yours open

I have the world open right now.

Funny enough... while this bug has cost me a good bit of work over both times it has happened... it is pretty cool at a basic level haha. It is like a time capsule. Every time I change anything within the chunk, and then exit and go back in, it just replaces everything like how it was when the bug first happened. pretty cool...

Okay could you send me a screenshot?

Also notice those repeating command blocks on the ground over there... you'll see em

Alright good

now do you see the items on the ground near those commands? It is the chunk up and to the right from that shot and is adjacent to the one with blazes in it

I've taken a look at a log file while having the world open and it keeps outputting

[File IO Thread/ERROR]: Failed to save chunk
java.io.UTFDataFormatException: encoded string too long: 97320 bytes
	at java.io.DataOutputStream.writeUTF(DataOutputStream.java:364) ~[?:1.8.0_51]
	at java.io.DataOutputStream.writeUTF(DataOutputStream.java:323) ~[?:1.8.0_51]
	at hn.a(SourceFile:33) ~[1.13.1.jar:?]
	at gy.a(SourceFile:422) ~[1.13.1.jar:?]
	at gy.a(SourceFile:63) ~[1.13.1.jar:?]
	at he.a(SourceFile:48) ~[1.13.1.jar:?]
	at gy.a(SourceFile:422) ~[1.13.1.jar:?]
	at gy.a(SourceFile:63) ~[1.13.1.jar:?]
	at gy.a(SourceFile:422) ~[1.13.1.jar:?]
	at gy.a(SourceFile:63) ~[1.13.1.jar:?]
	at hi.a(SourceFile:104) ~[1.13.1.jar:?]
	at hi.a(SourceFile:92) ~[1.13.1.jar:?]
	at bnu.a(SourceFile:270) [1.13.1.jar:?]
	at cdv.c(SourceFile:44) [1.13.1.jar:?]
	at cdv.run(SourceFile:35) [1.13.1.jar:?]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_51]
[10:43:21]

you can also set the time up a bit if you want I was just testing things with lighting... which actually exists outside the messed up chunk just like water... it stays even with no light source (still figuring that out)

The pile of repeating command blocks? Yes.

hmm

now my question... and I didn't think it would be a possibility will many other putting hundreds of long commands into one chunk... but it is possible it is too much information to save properly? What do you think the failed to save means?

Okay well just for a simple example...

pick up the command blocks then go away slightly from them then close the world

go back in and they will be there again

Funny enough I think I can tell you when the bug started occurring. It was when I dropped those items so I could look at my player data without as long of a string. When I dropped the second bit of items and went back over they took at least 2 seconds for me to pick them up (I couldn't until 2 secs had passed).

everything seemed normal after that but I guess it wasn't

By the way, where do I find the log file?

Really I think I mean how do I read it properly... I believe I do know where it says log

Did you try what I said before btw?

Log files and Gzip archives are found in .minecraft/logs. latest.log is just a simple .txt file so you should be able to read it easily with an application like Notepad.

I have seen that the pile of repeating command blocks will appear after a relog.

Yep. Okay a different way to prove this is... hmm okay notice the screenshot I put with the beds... place a bed between chunks. half of the bed will disappear. if you use a chest, the entire thing will disappear, not just half

I've completely cleaned out the chunk on my end and that seems to have fixed the issue. The chunk isn't resetting and the pile of repeating command blocks are all gone. Of course that doesn't mean everything's gone on your end, though.

Why do you think the game is failing to save the chunk? It also at least once failed to save a few others if not all of the surrounding ones.

what do you mean by cleared it out?

I'm unable to confirm the issue about the chests and beds disappearing, but that's probably just because it's caused by the chunk that keeps resetting.

It looks like the game was trying to save too much data to a chunk and failed. I've removed everything that existed in that chunk and it isn't happening anymore.

Yes, it is. To better understand what it does, I'd look at all of the screenshots.

But what do you mean by cleaning it out? The commands? or a good part of the chunk?

now the one thing I was thinking was maybe using "/reload" would work to fix it. But you've already caused it to save now so there isn't a point in doing it

By "cleaned" I meant literally removing every block in the chunk.

However, I think that just removing the command blocks is enough to fix it.

But see that is an issue for me... the commands are what I do so if it caused the area to not be usable what can I do??

This is the second world it has happened in no relation

This is still a bug it isn't "problem solved"

If you save the structures using structure blocks and/or save some of the commands as functions you should be able to remove the command blocks from the chunk and still have access to them via .nbt and .mcfunction files.

This is a duplicate of MC-102843.

I don't care about saving commands, I can do that just copying and pasting if I want. The issue is that this has happened TWICE now two different worlds and I just want to work with my commands/command blocks in peace.

Do we yet have an explanation for why this is happening? If the other post is a match for the bug I've described in now two bug reports, how hasn't anyone found anything significant?

Also I did not update block data. The only data I used was testing for a player with nbt of holding a certain item in a certain place... that is it! Do you think the bug could have occurred because it tried to read my entire player data? It would not be utilizing it for anything, only the slot and item check. But maybe with all of the items in my inventory, the commands collectively made the memory for the chunk overflow... this is just a theory.

Worth noting that I've had most of these commands in the world without a problem for a long time... they are also all very similar in their function and formatting. I'll give you the main string of nbt (and whole command) for many of the commands

/effect give @p[nbt={Inventory:[{Slot: 31b, id: "minecraft:sunflower", Count: 1b, tag: {RepairCost: 500, display: {Name: "{\"text\":\"Ring of Invisibility\"}"},Enchantments: [{lvl: 5s, id: "minecraft:"}]}}]},scores={RingT=300..1000}] minecraft:nausea 4 0 true

This is just testing for the nbt data of the player... this might be causing the problem described in the other post...

[12:07:58] PATICE27 has the following entity data: {HurtByTimestamp: 0, SleepTimer: 0s, Attributes: [{Base: 20.0d, Name: "generic.maxHealth"}, {Base: 0.0d, Name: "generic.knockbackResistance"}, {Base: 0.10000000149011612d, Name: "generic.movementSpeed"}, {Base: 0.0d, Name: "generic.armor"}, {Base: 0.0d, Name: "generic.armorToughness"}, {Base: 1.0d, Name: "generic.attackDamage"}, {Base: 4.0d, Name: "generic.attackSpeed"}, {Base: 0.0d, Name: "generic.luck"}], Invulnerable: 0b, FallFlying: 0b, PortalCooldown: 0, AbsorptionAmount: 0.0f, abilities: {invulnerable: 1b, mayfly: 1b, instabuild: 1b, walkSpeed: 0.1f, mayBuild: 1b, flying: 0b, flySpeed: 0.05f}, FallDistance: 0.0f, recipeBook: {recipes: ["minecraft:chest", "minecraft:piston", "minecraft:rail", "minecraft:wooden_pickaxe", "minecraft:powered_rail", "minecraft:charcoal", "minecraft:acacia_boat", "minecraft:dark_oak_button", "minecraft:jungle_boat", "minecraft:green_concrete_powder", "minecraft:end_crystal", "minecraft:pumpkin_pie", "minecraft:dark_oak_fence", "minecraft:light_weighted_pressure_plate", "minecraft:golden_shovel", "minecraft:wooden_axe", "minecraft:dark_oak_boat", "minecraft:dispenser", "minecraft:golden_sword", "minecraft:detector_rail", "minecraft:iron_door", "minecraft:shield", "minecraft:iron_nugget", "minecraft:sandstone", "minecraft:yellow_concrete_powder", "minecraft:golden_pickaxe", "minecraft:hopper_minecart", "minecraft:dark_oak_trapdoor", "minecraft:repeater", "minecraft:red_concrete_powder", "minecraft:iron_shovel", "minecraft:ladder", "minecraft:jack_o_lantern", "minecraft:sign", "minecraft:tripwire_hook", "minecraft:hopper", "minecraft:glass", "minecraft:redstone_torch", "minecraft:crafting_table", "minecraft:furnace_minecart", "minecraft:fishing_rod", "minecraft:blue_concrete_powder", "minecraft:iron_leggings", "minecraft:gold_nugget_from_smelting", "minecraft:white_concrete_powder", "minecraft:ender_chest", "minecraft:gold_nugget", "minecraft:iron_bars", "minecraft:iron_boots", "minecraft:iron_trapdoor", "minecraft:golden_chestplate", "minecraft:slime_ball", "minecraft:gray_concrete_powder", "minecraft:iron_helmet", "minecraft:iron_nugget_from_smelting", "minecraft:stick", "minecraft:light_blue_concrete_powder", "minecraft:light_gray_concrete_powder", "minecraft:dark_oak_stairs", "minecraft:iron_block", "minecraft:gold_ingot_from_nuggets", "minecraft:dark_oak_door", "minecraft:cooked_chicken", "minecraft:lime_concrete_powder", "minecraft:dark_oak_pressure_plate", "minecraft:beacon", "minecraft:golden_apple", "minecraft:activator_rail", "minecraft:golden_carrot", "minecraft:wooden_sword", "minecraft:flint_and_steel", "minecraft:iron_sword", "minecraft:red_sandstone", "minecraft:iron_chestplate", "minecraft:iron_pickaxe", "minecraft:wooden_shovel", "minecraft:cut_sandstone", "minecraft:magma_cream", "minecraft:black_concrete_powder", "minecraft:white_wool_from_string", "minecraft:purple_concrete_powder", "minecraft:cauldron", "minecraft:pink_concrete_powder", "minecraft:birch_planks", "minecraft:heavy_weighted_pressure_plate", "minecraft:golden_leggings", "minecraft:golden_axe", "minecraft:enchanting_table", "minecraft:tnt_minecart", "minecraft:lead", "minecraft:slime_block", "minecraft:spruce_boat", "minecraft:birch_boat", "minecraft:brown_concrete_powder", "minecraft:wooden_hoe", "minecraft:orange_concrete_powder", "minecraft:magenta_concrete_powder", "minecraft:shears", "minecraft:sandstone_slab", "minecraft:yellow_dye_from_sunflower", "minecraft:snow_block", "minecraft:dropper", "minecraft:dark_oak_slab", "minecraft:golden_boots", "minecraft:iron_axe", "minecraft:sandstone_stairs", "minecraft:ender_eye", "minecraft:iron_hoe", "minecraft:note_block", "minecraft:iron_ingot_from_iron_block", "minecraft:bow", "minecraft:cyan_concrete_powder", "minecraft:golden_helmet", "minecraft:snow", "minecraft:minecart", "minecraft:dark_oak_fence_gate", "minecraft:chest_minecart", "minecraft:oak_boat", "minecraft:clock", "minecraft:bucket", "minecraft:sticky_piston", "minecraft:fire_charge", "minecraft:golden_hoe", "minecraft:redstone", "minecraft:emerald", "minecraft:compass"], isFilteringCraftable: 0b, toBeDisplayed: ["minecraft:chest", "minecraft:piston", "minecraft:rail", "minecraft:wooden_pickaxe", "minecraft:powered_rail", "minecraft:charcoal", "minecraft:acacia_boat", "minecraft:dark_oak_button", "minecraft:jungle_boat", "minecraft:green_concrete_powder", "minecraft:end_crystal", "minecraft:pumpkin_pie", "minecraft:dark_oak_fence", "minecraft:light_weighted_pressure_plate", "minecraft:golden_shovel", "minecraft:wooden_axe", "minecraft:dark_oak_boat", "minecraft:dispenser", "minecraft:golden_sword", "minecraft:detector_rail", "minecraft:iron_door", "minecraft:shield", "minecraft:iron_nugget", "minecraft:sandstone", "minecraft:yellow_concrete_powder", "minecraft:golden_pickaxe", "minecraft:hopper_minecart", "minecraft:dark_oak_trapdoor", "minecraft:repeater", "minecraft:red_concrete_powder", "minecraft:iron_shovel", "minecraft:ladder", "minecraft:jack_o_lantern", "minecraft:sign", "minecraft:tripwire_hook", "minecraft:hopper", "minecraft:glass", "minecraft:redstone_torch", "minecraft:crafting_table", "minecraft:furnace_minecart", "minecraft:fishing_rod", "minecraft:blue_concrete_powder", "minecraft:iron_leggings", "minecraft:gold_nugget_from_smelting", "minecraft:white_concrete_powder", "minecraft:ender_chest", "minecraft:gold_nugget", "minecraft:iron_bars", "minecraft:iron_boots", "minecraft:iron_trapdoor", "minecraft:golden_chestplate", "minecraft:slime_ball", "minecraft:gray_concrete_powder", "minecraft:iron_helmet", "minecraft:iron_nugget_from_smelting", "minecraft:stick", "minecraft:light_blue_concrete_powder", "minecraft:light_gray_concrete_powder", "minecraft:dark_oak_stairs", "minecraft:iron_block", "minecraft:gold_ingot_from_nuggets", "minecraft:dark_oak_door", "minecraft:cooked_chicken", "minecraft:lime_concrete_powder", "minecraft:dark_oak_pressure_plate", "minecraft:beacon", "minecraft:golden_apple", "minecraft:activator_rail", "minecraft:golden_carrot", "minecraft:wooden_sword", "minecraft:flint_and_steel", "minecraft:iron_sword", "minecraft:red_sandstone", "minecraft:iron_chestplate", "minecraft:iron_pickaxe", "minecraft:wooden_shovel", "minecraft:cut_sandstone", "minecraft:magma_cream", "minecraft:black_concrete_powder", "minecraft:white_wool_from_string", "minecraft:purple_concrete_powder", "minecraft:cauldron", "minecraft:pink_concrete_powder", "minecraft:birch_planks", "minecraft:heavy_weighted_pressure_plate", "minecraft:golden_leggings", "minecraft:golden_axe", "minecraft:enchanting_table", "minecraft:tnt_minecart", "minecraft:lead", "minecraft:slime_block", "minecraft:spruce_boat", "minecraft:birch_boat", "minecraft:brown_concrete_powder", "minecraft:wooden_hoe", "minecraft:orange_concrete_powder", "minecraft:magenta_concrete_powder", "minecraft:shears", "minecraft:sandstone_slab", "minecraft:yellow_dye_from_sunflower", "minecraft:snow_block", "minecraft:dropper", "minecraft:dark_oak_slab", "minecraft:golden_boots", "minecraft:iron_axe", "minecraft:sandstone_stairs", "minecraft:ender_eye", "minecraft:iron_hoe", "minecraft:note_block", "minecraft:iron_ingot_from_iron_block", "minecraft:bow", "minecraft:cyan_concrete_powder", "minecraft:golden_helmet", "minecraft:snow", "minecraft:minecart", "minecraft:dark_oak_fence_gate", "minecraft:chest_minecart", "minecraft:oak_boat", "minecraft:clock", "minecraft:bucket", "minecraft:sticky_piston", "minecraft:fire_charge", "minecraft:golden_hoe", "minecraft:redstone", "minecraft:emerald", "minecraft:compass"], isFurnaceGuiOpen: 0b, isGuiOpen: 0b, isFurnaceFilteringCraftable: 0b}, DeathTime: 0s, XpSeed: -237037854, XpTotal: 710, playerGameType: 1, SelectedItem: {id: "minecraft:sandstone", Count: 1b}, Tags: ["Cursed"], seenCredits: 0b, Motion: [0.0d, -0.0784000015258789d, 0.0d], UUIDLeast: -6984438403199157692L, Health: 20.0f, foodSaturationLevel: 5.0f, Air: 300s, OnGround: 1b, Dimension: 0, Rotation: [107.287415f, 35.02684f], XpLevel: 22, Score: 710, UUIDMost: -5143474442851367229L, Sleeping: 0b, Pos: [24.659982230332727d, 56.0d, 22.69876906762061d], Fire: -20s, XpP: 0.4305557f, EnderItems: [{Slot: 0b, id: "minecraft:water_bucket", Count: 1b}, {Slot: 1b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 5b, id: "minecraft:emerald", Count: 1b}], DataVersion: 1628, foodLevel: 20, foodExhaustionLevel: 0.0f, HurtTime: 0s, SelectedItemSlot: 7, ActiveEffects: [{Ambient: 0b, ShowIcon: 0b, ShowParticles: 0b, Duration: 7, Id: 8b, Amplifier: -1b}], Inventory: [{Slot: 0b, id: "minecraft:repeating_command_block", Count: 14b, tag: {BlockEntityTag: {conditionMet: 1b, auto: 0b, powered: 1b, CustomName: "{\"text\":\"@\"}", Command: "/effect give @p[nbt={Inventory:[{Slot: 31b, id: \"minecraft:sunflower\", Count: 1b, tag: {RepairCost: 500, display: {Name: \"{\\\"text\\\":\\\"Ring of Invisibility\\\"}\"},Enchantments: [{lvl: 5s, id: \"minecraft:\"}]}}]}] minecraft:invisibility 1 0 true", LastExecution: 316541L, id: "minecraft:command_block", SuccessCount: 0, LastOutput: "{\"extra\":[{\"color\":\"red\",\"extra\":[{\"translate\":\"argument.entity.notfound.entity\"}],\"text\":\"\"}],\"text\":\"[13:07:34] \"}", TrackOutput: 1b, UpdateLastExecution: 1b}, display: {Lore: ["(+NBT)"]}}}, {Slot: 1b, id: "minecraft:repeating_command_block", Count: 14b, tag: {BlockEntityTag: {conditionMet: 1b, auto: 0b, powered: 1b, CustomName: "{\"text\":\"@\"}", Command: "/scoreboard players add @p[nbt={Inventory:[{Slot: 31b, id: \"minecraft:sunflower\", Count: 1b, tag: {RepairCost: 500, display: {Name: \"{\\\"text\\\":\\\"Ring of Invisibility\\\"}\"},Enchantments: [{lvl: 5s, id: \"minecraft:\"}]}}]},scores={RingT=0..998}] RingT 1", LastExecution: 316561L, id: "minecraft:command_block", SuccessCount: 0, LastOutput: "{\"extra\":[{\"color\":\"red\",\"extra\":[{\"translate\":\"argument.entity.notfound.entity\"}],\"text\":\"\"}],\"text\":\"[13:07:35] \"}", TrackOutput: 1b, UpdateLastExecution: 1b}, display: {Lore: ["(+NBT)"]}}}, {Slot: 2b, id: "minecraft:repeating_command_block", Count: 14b, tag: {BlockEntityTag: {conditionMet: 1b, auto: 0b, powered: 1b, CustomName: "{\"text\":\"@\"}", Command: "/effect give @p[nbt={Inventory:[{Slot: 31b, id: \"minecraft:sunflower\", Count: 1b, tag: {RepairCost: 500, display: {Name: \"{\\\"text\\\":\\\"Ring of Invisibility\\\"}\"},Enchantments: [{lvl: 5s, id: \"minecraft:\"}]}}]},scores={RingT=900..1000}] minecraft:blindness 2 1 true", LastExecution: 316579L, id: "minecraft:command_block", SuccessCount: 0, LastOutput: "{\"extra\":[{\"color\":\"red\",\"extra\":[{\"translate\":\"argument.entity.notfound.entity\"}],\"text\":\"\"}],\"text\":\"[13:07:36] \"}", TrackOutput: 1b, UpdateLastExecution: 1b}, display: {Lore: ["(+NBT)"]}}}, {Slot: 3b, id: "minecraft:repeating_command_block", Count: 14b, tag: {BlockEntityTag: {conditionMet: 1b, auto: 0b, powered: 1b, CustomName: "{\"text\":\"@\"}", Command: "/scoreboard players remove @a[nbt=!{Inventory:[{Slot: 31b, id: \"minecraft:sunflower\", Count: 1b, tag: {RepairCost: 500, display: {Name: \"{\\\"text\\\":\\\"Ring of Invisibility\\\"}\"},Enchantments: [{lvl: 5s, id: \"minecraft:\"}]}}]},scores={RingT=1..1000}] RingT 1", LastExecution: 316598L, id: "minecraft:command_block", SuccessCount: 0, LastOutput: "{\"extra\":[{\"color\":\"red\",\"extra\":[{\"translate\":\"argument.entity.notfound.entity\"}],\"text\":\"\"}],\"text\":\"[13:07:37] \"}", TrackOutput: 1b, UpdateLastExecution: 1b}, display: {Lore: ["(+NBT)"]}}}, {Slot: 4b, id: "minecraft:repeating_command_block", Count: 14b, tag: {BlockEntityTag: {conditionMet: 1b, auto: 0b, powered: 1b, CustomName: "{\"text\":\"@\"}", Command: "/effect give @p[nbt={Inventory:[{Slot: 31b, id: \"minecraft:sunflower\", Count: 1b, tag: {RepairCost: 500, display: {Name: \"{\\\"text\\\":\\\"Ring of Invisibility\\\"}\"},Enchantments: [{lvl: 5s, id: \"minecraft:\"}]}}]},scores={RingT=990..1000}] minecraft:hunger 1 0 true", LastExecution: 316636L, id: "minecraft:command_block", SuccessCount: 0, LastOutput: "{\"extra\":[{\"color\":\"red\",\"extra\":[{\"translate\":\"argument.entity.notfound.entity\"}],\"text\":\"\"}],\"text\":\"[13:07:39] \"}", TrackOutput: 1b, UpdateLastExecution: 1b}, display: {Lore: ["(+NBT)"]}}}, {Slot: 5b, id: "minecraft:repeating_command_block", Count: 14b, tag: {BlockEntityTag: {conditionMet: 1b, auto: 0b, powered: 1b, CustomName: "{\"text\":\"@\"}", Command: "/execute at @a if block ~ ~-0.1 ~ air run effect give @p[nbt={Inventory:[{Slot: 100b, id: \"minecraft:iron_boots\", Count: 1b, tag: {RepairCost: 500, display: {Name: \"{\\\"text\\\":\\\"Long Fall Boots\\\"}\"},Enchantments: [{lvl: 10s, id: \"minecraft:infinity\"}]}}]}] minecraft:jump_boost 1 255 true", LastExecution: 357954L, id: "minecraft:command_block", SuccessCount: 0, TrackOutput: 1b, UpdateLastExecution: 1b}, display: {Lore: ["(+NBT)"]}}}, {Slot: 6b, id: "minecraft:repeating_command_block", Count: 3b, tag: {BlockEntityTag: {conditionMet: 1b, auto: 0b, powered: 1b, CustomName: "{\"text\":\"@\"}", Command: "/effect give @p[nbt={Inventory:[{Slot: 31b, id: \"minecraft:sunflower\", Count: 1b, tag: {RepairCost: 500, display: {Name: \"{\\\"text\\\":\\\"Ring of Invisibility\\\"}\"},Enchantments: [{lvl: 5s, id: \"minecraft:\"}]}}]},scores={RingT=800..1000}] minecraft:slowness 1 0 true", LastExecution: 316616L, id: "minecraft:command_block", SuccessCount: 0, LastOutput: "{\"extra\":[{\"color\":\"red\",\"extra\":[{\"translate\":\"argument.entity.notfound.entity\"}],\"text\":\"\"}],\"text\":\"[13:07:38] \"}", TrackOutput: 1b, UpdateLastExecution: 1b}, display: {Lore: ["(+NBT)"]}}}, {Slot: 7b, id: "minecraft:sandstone", Count: 1b}, {Slot: 8b, id: "minecraft:lava_bucket", Count: 1b}, {Slot: 10b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 11b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 12b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 13b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 15b, id: "minecraft:repeating_command_block", Count: 14b, tag: {BlockEntityTag: {conditionMet: 1b, auto: 0b, powered: 1b, CustomName: "{\"text\":\"@\"}", Command: "/effect give @p[nbt={Inventory:[{Slot: 31b, id: \"minecraft:sunflower\", Count: 1b, tag: {RepairCost: 500, display: {Name: \"{\\\"text\\\":\\\"Ring of Invisibility\\\"}\"},Enchantments: [{lvl: 5s, id: \"minecraft:\"}]}}]},scores={RingT=300..1000}] minecraft:nausea 4 0 true", LastExecution: 316522L, id: "minecraft:command_block", SuccessCount: 0, LastOutput: "{\"extra\":[{\"color\":\"red\",\"extra\":[{\"translate\":\"argument.entity.notfound.entity\"}],\"text\":\"\"}],\"text\":\"[13:07:33] \"}", TrackOutput: 1b, UpdateLastExecution: 1b}, display: {Lore: ["(+NBT)"]}}}, {Slot: 16b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 17b, id: "minecraft:redstone_block", Count: 1b}, {Slot: 18b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 19b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 20b, id: "minecraft:flint_and_steel", Count: 1b, tag: {Damage: 0}}, {Slot: 21b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 22b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 23b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 24b, id: "minecraft:white_shulker_box", Count: 63b}, {Slot: 25b, id: "minecraft:dark_oak_planks", Count: 1b}, {Slot: 26b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 27b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 28b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 29b, id: "minecraft:white_shulker_box", Count: 59b}, {Slot: 30b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 31b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 32b, id: "minecraft:white_shulker_box", Count: 1b}, {Slot: 33b, id: "minecraft:minecart", Count: 1b}, {Slot: 34b, id: "minecraft:polished_andesite", Count: 1b}, {Slot: 35b, id: "minecraft:beacon", Count: 1b}, {Slot: 100b, id: "minecraft:iron_boots", Count: 1b, tag: {RepairCost: 500, display: {Name: "{\"text\":\"Long Fall Boots\"}"}, Enchantments: [{lvl: 10s, id: "minecraft:infinity"}], Damage: 0}}], foodTickTimer: 0}

So I guess we can see how a player's inventory FULL of command blocks with data in them could cause a massage string of data for the player to be created and then recorded from the data get command

just hit the arrow on the comment to get rid of it mostly

I believe this may have also been the issue for the last time it happened... the more I messed around with the commands, the more commands I collected in my inventory, collecting more data. It was different the first time though as my inventory was reset as well... not just the blocks and entities around me... this may be because there was an overflow of data for the player information so it couldn't save past a point.

Also the world (first one) only went back to the way it was way before I saved once. It never was repeatable... while with the second world it is (continues to be repeatable).

As described in MC-102843, the last output text field is so long, the chunk is no longer able to be saved with that string. You aren't getting any lag like described in that report, since their issue causing the last output field to become long was a recursive operation and text field became longer and longer every cycle.

So in other words what you are saying is that the same issue is occurring, but not causing lag because in the other report, the command data was constantly being changed and the data had to be updated constantly (versus not being changed and therefore not being updating from what is was last)? I guess I could compare that to having to paste that long string I commented before (being delayed and almost crashing Chrome), versus pasting it ten times a second. Is that a good way of understanding it?

If so, I suppose it is really a matter of scale in the sense of how much the overflow is and how often it occurs.

Also, how does that explain my player inventory being reverted back as well? That isn't included in the chunk data right?

Only happened in the first world