The bug
You can fall through the world at x:65536 z:65535 by slowly walking against blocks.
How to reproduce
Make a world, and teleport to the provided coordinates.
Seed: 2124988472 Coordinates: /tp 65534.5 68 65535.5 180.6 50
Don't move your mouse, walk forward and you'll go slowly towards x:65536 (to the right).
→ ❌ While moving to x:65536, your screen starts stuttering and you fall through the world
Thanks to xp2_882030kgz010602 for discovering.
Related issues
is duplicated by
Attachments
Comments


I think it's because "the math that governs the internal position of blocks actually causes a phenomenon that you can't even see yet, which allows you to fall right through the world all the way into the void.
(by AntVenom)"

Identical to MCPE-19828. It could be marked as a duplicate of this, given that this report explains it better and wasn't written by my mentally unstable 15 year old self.

only relates to MCPE-19828

Ant venom Released a video on this bug.

Fixed in 1.11.0.7

The fix for this has apparently been reverted in 1.11.0.8.

I've tested AntVenom's 2048 block distance as well, and it still happens in the latest version. Honestly, it shouldn't be possible to fall through the world at 2048 blocks.

I really really hope they fix this soon but leave the Farlands in. I really want to be able to walk around the farlands, but due to this precision point loss falling through the world is inevitable past about 8 million blocks.

Does this always happen if you stop moving at integer coordinates, or just when you cross a power of 2 at a slow speed? If it’s the latter, this bug would be easy to avoid; just like fault lines are risky IRL, powers of 2 are risky in Minecraft.
As someone who's interested in Far Lands glitches, I'd actually prefer this not fixed, as long as it is easy for players to avoid.
Edit: I did some testing in version 1.12.1. When I cross a power of 2 at the slowest speed, I fall through the world, as this bug states, but I also start falling through when I move to nearby locations, including before the power of 2. When I exit and re-enter the game, I stop falling through until I trigger the glitch again. This suggests that the initial fall puts the player in a state that allows further falling. If this state is that the player's hit box is 0, this would also explain why you fall through the world past 8,388,608 blocks, since the 0.3 blocks of hit box on each side round down to 0. However, I could be completely wrong, so I am not convinced that the glitch is as easy to avoid as I thought. Because of this, the bug should get fixed.

Tested in 1.13.0,
It is still unresolved. Created a new world, teleported to 65568, 66, 65536 and glided slowly through the middle until it happened.
This should get fixed immediately as it makes travelling further than 2048 possibly be unplayable

I could not reproduce this bug in 1.13.3 on iOS. I started moving at the appropriate speed. I noticed the jitter associated with excessive coordinates (which I expected). As soon as I hit 65536, the jitter increased (frame rate cut in half) so I knew the floating-point precision errors increased at that moment. I became unable to move a fraction of a block after this, instead of right at 65536. Previously, I would become unable to move as soon as I cross a power of 2, and I would fall through the world.
This new effect happens at 131072 and 262144. I fell through the world at 524288, which is far enough out that it is not a concern.
Edit: A similar phenomenon happens in 1.14.0 (again on iOS) but I begin to fall through the world at 131072 blocks. While this is arguably worse, it is still beyond the "normal" coordinates, and the game starts to break anyway.

It works it is a bug with Bedrocks Code it is because of the poisoning of the player and every 2 block you travel this becomes more common it is possible to fall though the world at any point starting at 2 blocks out from 0,0. Because of the code and Lad Generation Algroithem this is possible and Happens at 8,000,000 something blocks out and it will happen it is possible to fall through at any point more common past 1M block

(Tested in 1.14.1 Hotfix on iOS)
I noticed more information about this bug that probably tells us what causes it how how to fix it. I did most of the testing at x: 131072 (the game is just starting to break at this point) but I can confirm it is possible to fall through the world at 2048 blocks.
If I start less than 0.3 blocks from the boundary, I stop moving without falling through the world (Note: 0.3 is half the size of the player's hitbox). This even works at 1,048,576 blocks, which is well outside the playable region.
If I start more than 0.3 blocks from the boundary, I fall through the world. Furthermore, once I am within 0.3 blocks of the boundary, my movement becomes slower and more jittery.
If I start less than 0.3 blocks from the boundary, move closer at the slow speed, move away at a faster speed, and repeat this process, I can eventually cross the boundary and fall through the world. This holds even if I was never more than 0.3 blocks of the boundary.
If I place a block so that I shouldn't be able to cross the boundary, I drift anyway. As I get closer to the boundary, I am definitely in a position where I should be inside the block. If the block is at head height, I get an x-ray glitch.
If I start drifting towards the boundary, then stop, I can fit in the space between a wooden fence and a nether brick fence, which is not normally possible. I am pushed out when I use
/tp @s ~ ~ ~
. If I go even closer to the boundary before backing out, I can fit in the space between 2 honey blocks, which you are definitely not supposed to be able to do.
The above information implies that the bug is an error in the cached coordinates of the player's hitbox corners. Normally, all hitbox corners move at the same speed, but I think this bug is caused by some corners moving at different speeds. Suppose you start at x: 2047.69, and you move at the critical speed. Then the following would happen:
At first, your entire hitbox is within the 2048 block boundary.
When you reach 2047.70, the front side of your hitbox is at 2048. Due to the change in floating-point precision errors, the front side thinks you are not moving, so it stays at 2048.00. This explains why having a block across the 2048-block boundary does not stop you from continuing to move.
Since only one side of your hitbox is moving, the speed at which your center is moving cuts in half, which explains why your movement gets slower and more jittery.
As you continue to move, your hitbox slowly collapses, which is why you become able to fit in smaller spaces as you progress.
When the other side of your hitbox reaches 2048, your hitbox width is zero, which makes you able to fall through the edges of blocks. Since you are already at integer coordinates, you start falling through the world almost immediately.
If the front end of your hitbox is already past the boundary, then you still have a nonzero hitbox width at the end. If you hitbox is already partially collapsed, you can start less than 0.3 blocks from the boundary, and your hitbox will still be entirely within the boundary. This should explain all of my observations.
A possible fix would be to reset the player's hitbox periodically. It already resets when you exit and re-enter the game, when you use the /tp
command, and in some other situation(s) that I am not able to reproduce. I measured and calculated that at 16384 blocks, there is a gap of just over 30 blocks between when you start moving and when you fall through the world. Thus, resetting the player's hitbox every 30 seconds would make it impossible to fall through the world at 16384 (32768 would be the lowest coordinates at which you can fall through the world). I am not sure whether the playable region should extend beyond 32768 blocks, but you get the idea.

This also happens the other way round: while your hitbox can shrink to 0 by passing through the 2^n^ line from the smaller coordinates side, your hitbox can also expand by passing through it from the other side (I tested it by going slowly from 16384 to 16383 several times, and my hitbox eventually became larger than 10 blocks). So maybe an always fixed hitbox size is better.

I don't know why this bug is still not fixed. It's almost 2 years after creating this thread. I'm not playing on my Bedrock Edition survival world just because of this bug. I don't care if the FarLands/StripeLands will be deleted, I just want to play Bedrock Edition normally without worrying that I will randomly fall through the world, die and lose all my stuff. I want to travel around the world and find rare biomes ! Please try to fix that bug before the end of vacation 2020 ! We need to make this thread more popular !

Szymon, this is not a bug that you should be concerned about unless you are purposefully trying to fall through the world. It is a problem with the very way the game stores the position of entities, and furthermore should not prevent you from playing the game until you are planning on an expedition that requires you to walk in one direction for 30k blocks or more. To fix this bug would either require a fixed hitbox like mentioned above, or a rewrite of how the game handles an entity's position.

An attachment with a disallowed file extension has been removed from this ticket.
Executable files and documents are not allowed as attachments.
Please attach crash reports, log files and screenshots as they are instead of pasting them into a document.
-- I am a bot. This action was performed automatically! Please report any issues in Discord or Reddit

Can confirm for 1.16.100/1.16.200.56.

There's chance to make you fall from any seeds where you go to coordinate to walk for:
0.1/2 chance to find where you wander to walk on collision-less block
(Even the gap of -->|<-- block on center will fall you down)

Affects Version 1.16.200

Works as intended: MCPE-19828 apparently even though it shouldn't do this i feel bad for any huge server

That ticket was resolved a little over four years ago. Even if Mojang changed hasn't their mind, this ticket is still open, and has an ADO. I would rather redirect anyone who has found that ticket to this one just so there isn't any confusion of what's happening in today's time.

Fixed with the help of a behaviour pack and command blocks!
I tried to do my best and fix the bug with a behaviour pack edit, but it turns out that i fixed it with that but with command blocks too
However, this may have some extra visual bugs regarding the player's size.
Video:
https://clipchamp.com/watch/Pv1ErHt8vfw
Did not attach the behaviour pack due to copyright reasons but you can still install the patch:
Download the Size Scaler Addon from https://mcpedl.com/size-scaler-addon/
Open the addon with WinRar or a software that opens archives;
Replace player.json file in the "entities" folder with the new one attached to this bug report:
Open the new addon file with Minecraft and install the behaviour pack;
Attach the behaviour pack to your world;
Enable all Experiments (Holiday Creator Features; Creation of Custom Biomes; Additional Modding Capabilities; Enable Gametest Framework);
Enter your world;
Execute command:
/gamerule commandblockoutput false
9. Set up 2 command blocks like this:
1. Command: /event entity @a event:scale_2
Repeat Unconditional Always Active Delay in Ticks: 7
2. Command: /event entity @a event:scale_normal
Repeat Unconditional Always Active Delay in Ticks: 7
10. Stand on top of one of the command blocks and execute command:
/tickingarea add ~2 ~2 ~2 ~-2 ~-2 ~-2 bugfixcommands
This should work and should fix the bug!
Have fun! 🙂
Edit:
I attached the world too for you to simply try it out (change the extension to mcworld if it is not):
https://filebin.net/qwx5yvpfuoumsowm
(link expires on 5/May/2021)
Edit 2: I created this comment for those who are "too scared" to play on survival, knowing that they will randomly fall through the ground, die, and lose everything; and to prove how easy is this bug to fix.

You don't even have to go that far to see this bug! Just going past 32768 blocks will cause the screen to jitter. You can even see it at 16384 blocks. It's ridiculous. The bug has been in the game for YEARS. If you want to travel more than 16000 blocks normally, go play java. Please, fix this bug. I am shocked that it wasn't fixed when it was discovered as this is seriously game breaking.

Can confirm in Minecraft Java Edition.
But don't worry. It happens at just over 549755813888 blocks away! (but still very hard at this distance)
It was tested (and i recommand to test it like this) at 8796093022208 blocks away in version 1.2.5.
There is NO WAY to reproduce this in java edition vanilla as it's limited to 30000000 blocks, but with very powerful mod you can do that, and you can pass 2147483647 blocks too, and there is a mod for that!
This mod has NOTHING to do with falling through the world, what it does is it only just expands the world limit to the 64 bit integer limit. Anyways, further is information in this video: www.youtube.com/watch?v=F8cMZA8J2Hk (download and credits in the description of the video)
Edit: So i think this happens in every sandbox game, not only Minecraft. Almost every sandbox game stores hitboxes in floating point numbers, either 32 bit or 64 bit, but if the player moves at a critical speed and one edge of the player's hitbox is before a power of 2, and the other is after a power of two, the one before the power of 2 moves, while the other one not. This causes the player's hitbox to shrink or expand, and like this the hitbox width can reach 0 (the "null" state), which can disable the collisions of the hitbox.

The issue is a won't fix, unfortunately.
You can vote for an issue for jittering when going through certain coordinates - MCPE-65298.

At least add a world border at the limit of normality

Reply to @unknown & @unknown: Adding a world border to such small distances will be more terrible and actually harder than literally fixing the bug. I barely know something about C++ and how Minecraft Bedrock Edition is coded and this kinda stuff AND I LITERALLY FIXED THE BUG! Don't believe me? Check out my older comment that is the 6th comment before this one.
IMPORTANT EDIT: I attached a tutorial on how to fix the bug by yourself to the bug report. It is probably going to get removed by a moderator or a Mojang employee, but i've done it anyways to raise awareness (that this bug is sooo easy to fix): Working Fix.txt
EDIT 2: Reattached the working fix with some changes to make it more clear

Confirmed in 1.19.83.
Principle:
The positions of the centers of entities are stored in NBT, the positions of the hitbox corners are stored in memory. If the player is crossing a power of 2, these corners may move at different speeds, thus changing the hitbox size. The hitbox size resets to 0.6 in certain situations, such as reloading the world, using the /tp command, and others. However, the player can shrink to size 0, making it possible to fall through the edges of blocks and into the void.
When a player is located at X/Z(2^n-1) and moving towards that axis at a speed of 2^(n-24) blocks per tick (the slowest speed to move between 2^(n-1) and 2^n), two hitbox corners close to 2^n will stop moving at 2^n because that speed couldn't move after 2^n. But another two hitbox corners are located at a coordinate smaller than 2^n, so they could move until they reach 2^n, then the width of player's hitbox will become 0 and fell through the world.
So you could fell through world by moving at 0.25b/t(5m/s) from 4194303 to 4194304, 0.125b/t(2.5m/s) from 2097151 to 2097152, 1.25m/s from 1048575 to 1048576, 0.625m/s from 524287 to 524288, etc. The lowest coordinate for me to reproduce this currently is 8192(Requires ~0.00976m/s speed)

Can't Mojang just calculate the block you are supposed to collide with using Integers rather than floating point? I mean, it's fine by me for them to use Floating point for vertical block collision since at Y=320 floating point precision is still at 0.000030517578125 units per increment. Mojang, if you are reading this, you have just been given a idea as to how you can fix this bug. And I beg of you, please fix it, it objectively impairs playability of the game. I would expect Mojang to put this at high priority.

This bug is critical and should be fixed. It essentially limits the 'usable' part of the world to 131072 blocks on each side, as outside of the 131072 block square, there is a risk of falling through the world.