[MC-179858] Maps show stone-like pattern despite it not being there

Moderator note

For anyone who opened their world in 20w17a and is still experiencing this issue in versions after 20w17a:
Try optimizing the world:
Important: Depending on the world size this may take a while.

Client:
1. Select the world on the world selection screen
2. Press the "Edit" button
3. Select "Optimize World"
4. Check "Erase cached data"
5. Press "Create backup and load"
6. Revisit the area located on the map to update it
Server:
1. Create a backup by copying the world folder
2. Start with --forceUpgrade --eraseCache

If you are still experiencing this issue after trying the steps above, please comment and attach the world (in the version before you opened it in the latest version of the game) as zip file.

I started up the new version and when I looked at my maps it showed them as seen in the screenshot

Linked issues

is duplicated by 173

MC-179844 Empty maps get corrupted when used Resolved

MC-179859 Maps have grey lines which aren't supposed to be there on them Resolved

MC-179875 [Dupe of MC-17858] Map does not take info of surface block Resolved

MC-179885 Maps get destroyed by strange stripes Resolved

MC-179894 Maps glitched Resolved

168 more links

relates to 1

MC-179952 Height map data doesn't get converted Resolved

Attachments

Comments 37

Chanderule 2020-04-22T18:57:09Z

This is just a theory but maybe it ties in with the "underground rain" bug? It seems like some parts of the map simply ignore the surface blocks and might look for the next one right under some air blocks, in this case it could show caves - rain could behave similarly, bypassing the actual ground and only falling down in the caves

Levchenko Vitaliy Viktorovich 2020-04-22T18:58:33Z

Had the same problem. This affects not only maps but block behaviors themselves. If you see rain in this world you should be able to see it going through some solid blocks. When those blocks are removed and placed back - they behave normally again. This must be due to the new block storage tweaks in the snapshot.

Logan 2020-04-22T21:41:16Z

I do as well after updating and I am on java edition and this is super annoying and needs to be fixed. It also does this with new maps in the world.

Jason Winzenried 2020-04-23T06:21:08Z

this is indeed the same bug as "underground rain" as seen at https://bugs.mojang.com/browse/MC-180090 and probably others

worlds from before 20w17a have their heightmaps messed up when loaded in 20w17a. Can see with f3: the S and M values (for WORLD_SURFACE and MOTION_BLOCKING) are just completely random values. A world newly created with the new snapshot does not show this issue for me.

LethalChicken 2020-04-26T02:02:18Z

also beacons can pass through these blocks

27 more comments

Tyler Smith 2020-04-29T09:32:32Z

I hope this is also the only issue with what's causing my ice farm to grow oddly in lines. 😛 screenshot

brickticks 2020-04-29T16:35:18Z

This is still not fixed as of 20w18a, still happening to me.

David Dersigny 2020-04-29T16:44:26Z

It is fixed if you reload the world from before 20w17a. Now it would be nice to be able to "reset" the heightmap from a world corrupted by 20w17a (commands or external editor) but I don't know how to do that, sorry.

violine1101 2020-04-29T16:45:04Z

As far as I'm aware, worlds opened in 20w17a will continue to be affected by this issue. Optimizing the world will probably fix that for worlds opened in that version.

David Dersigny 2020-04-29T16:47:51Z

I confirm that optimizing the world, with "erase cache" checked, fixes the world, thanks 🙂

val59000mc 2020-04-29T17:55:23Z

How do you "optimize" the world on a server ?

violine1101 2020-04-29T18:11:11Z

Start the server with the command arguments --forceUpgrade --eraseCache.

Ryan Akitt 2020-04-29T21:10:14Z

Im having this issue and I never used 20w17a. Iv'e only used 20w18a

Josiah Abram Guthrie 2020-04-29T22:21:11Z

Dear, Bartosz Bok (Assignee),
@unknown (Last dev who responded), and whom else it may concern,
This is still a major Bug in Snapshot 20w18a, as shown in the pictures I just added to this report.

When player walks/ flies around to update their map(s), this Bug occurs.

My system/version is MC Java Snapshot 20w18a Windows 10 version 1909.

Please Have this Bug Re-Opened and maybe check it more thoroughly during that time. I'm not trying to be rude when I say that, its just that in my 3.5 years (and counting) of playing Minecraft, I've seen Bugs get fixed and thought to be long gone, resurface after a long time, or they somehow get added to new updates. I am not at all saying that you moderators and developers are bad, y'all are excellent at what you do. That's the truth. The fact is: No One Is Perfect (Except our Lord God Almighty ( If you believe in Him. No Offense if you don't.)) and it's just our nature for things like this to creep in sometimes.

Thank y'all for all that you do,

JAG

J Hi 2020-04-30T00:35:51Z

so how do i fix this yes i read your messages i dont know what you mean by Start with --forceUpgrade --eraseCache how do i do that where do i do that{{ is it a button somewhere do i type it somewhere. i use aternos to host my server do i type it in console or the game. do i use the .minecraft files that came with the game. what do i do help.}}

Will Runge 2020-04-30T01:34:30Z

Can confirm that starting server with --forceUpgrade and --eraseCache fix the maps. I didn't update the entire map, but you can see that the area within my range is fixed.

[media]

James Croft 2020-04-30T07:39:49Z

With @Josiah Abram Guthrie on this one, still appears to be an issue with 20w18a. Maps created with an empty map or attempting to regenerate existing broken maps is not fixing them (running server).

violine1101 2020-04-30T10:45:36Z

Please read the large yellow/red box in this ticket's description. Worlds you have opened in 20w17a will remain broken until you fix them. Additionally, in order to get the maps to render properly, you need to explore the affected areas again.

J Hi 2020-04-30T17:03:15Z

yeah i read the yellow box but where do i do that for server

Josiah Abram Guthrie 2020-04-30T19:09:52Z

Just want to confirm that the given solution worked successfully and my maps are back to normal.

Thanks for the help

JAG

violine1101 2020-05-01T21:11:20Z

@unknown, it says in the yellow box:

Server:
Create a backup by copying the world folder
Start with --forceUpgrade --eraseCache

shadow 2020-05-02T08:36:49Z

ty for the info but need the step to do if you upgrade the server version from snapshot 20w16 a to 20w17a then to 20w18 a?

violine1101 2020-05-02T10:38:23Z

Whenever you load a world in 20w17a, it will be broken and needs to be repaired.

If you skip 20w17a, the error will not occur.

Andrew 2020-05-02T23:40:08Z

I have a server started /w 20w07a on VPS /w Ubuntu. A few days ago, I started in 20w17a (the maps were normal) and then now I'm playing in 20w18a (today, playing the last snapshot, I saw that maps were corrupted., I did as you say (Start with: --forceUpgrade --eraseCache), but the maps are still bugged, can someone help me?

SullyTheUnusual 2020-05-03T00:44:53Z

After running --forceUpgrade --eraseCache, you have to hold the maps and revisit the area. They will update without the grainy texture.

shadow 2020-05-05T09:20:41Z

i have done all and the map in my hand is the new one the map ind the frame is the old one that whas ufter updating it to show changes i made the map in my hands whas just created and have the same textur banner props what have i make wrong ? playing on a multiplayer server 20w18a and the server owner have dowloadet the map the stoped the server make the edit over singelplayer and reuplodet the map to the server so i think the map issue sholld not more exist after all steps are done. the other maps parts still ok then i have never update them.

[media]

Juanma 2020-05-06T10:18:58Z

I fixed the issue following the steps above. However, I had to (re)explore the area carrying my maps to (re)paint them.

Noah 2020-05-08T18:18:33Z

I don't understand how to start with --forceUpgrade --eraseCache on my server. Is that a command? Can someone explain?

violine1101 2020-05-13T11:39:59Z

Yes, append these command line arguments to the command you usually start the server with. After you have started the server with these arguments once, you can remove them again. Note that it might take quite a while for the server to optimize the world.

Kyle Jin 2020-05-30T21:20:52Z

This bug still hasn't been fixed and now it's 20w21a. I've reported yesterday and I hope someone fix this immediately.

GGreaper 2020-06-23T23:49:49Z

i optimised this world a while ago but im still having trouble with the lines
download for my world:
http://www.mediafire.com/file/09fdrmnlbwn1l2g/world_upgrade_fixed.zip/file

boq 2020-06-24T07:02:29Z

You need to check "Erase cached data" on upgrade screen, otherwise problem will persist

Xylonn72 2020-06-27T13:49:32Z

I followed the steps to fix the bug, but my game keeps crashing when I try doing that. My world is 2.72 GB.

Will Knox 2020-06-30T08:59:21Z

I'm confused by the lack of explanation of a fix for servers what do I have to do?

wobst.michael 2020-06-30T09:15:44Z

It's clearly explained in the description.

Will Knox 2020-06-30T09:42:01Z

all it says is make a backup --forceupgrade --erasecache I don't know what that means, are they commands? where do I put them?

connor beachy 2021-01-20T19:31:31Z

it seems what the problem is is that in random areas it shows the second highest block that has air above it. IDK if this with helps anything.