The bug
This is a rendering bug to do with Tile Entities in a chunk. I have provided screenshots which aim to show how to reproduce too.
If you have 64 or more Tile Entities within the same chunk and then "delete" them, using either /fill, /clone or (if they are signs) retracting them using pistons, when you place a new Tile Entity in that same spot, the previous Tile Entity will render over that or instead of the new Tile Entity.
For example, if you have a wall of 64 chests, do /fill to get rid of them and then place a beacon down where one chest was, you'll get a chest that's rendered inside a beacon. If you place a sign down you get an error that says "Unable to locate sign".
All rendering errors and effects are cleared with a relog, so perhaps this has something to do with the way chunks are updated or saved?
How to reproduce
Press
F3+Gto make sure the blocks you are filling are in the same chunkUse for example the
/fillcommand to place 64 or more tile entities/fill ~1 ~ ~ ~5 ~4 ~4 enchanting_tableUse for example the
/fillcommand again to replace these tile entities with different tile entities/fill ~1 ~ ~ ~5 ~4 ~4 ender_chest
Code analysis
Code analysis by @unknown can be found in this comment.
Linked issues
is duplicated by 10
relates to 6
MC-77033
/clone /fill of tile entity (TE) over a TE renders the old TE
Resolved
MC-46094
Using fill/clone which replaces mobspawner and keeps its fire particle
Resolved
MC-94240
Placing signs where cloned signs once were will autofill their text field.
Resolved
MC-123304
"Ticking block entity" NullPointerException Game crash 64 Pistons in 1 chunk
Resolved
MC-123432
Snapshots are leaking tile entity data through to world save
Resolved
Attachments
Comments 14
Actually, this is /fill command not doing its job right. Fill command doesn't destroy old tile entities, just their blocks and since MC has custom renderers for some tile entities, old renderer remains.
As old tile entity remains in the same place and when placing another you create a new one, you end up with two tile entities in the same place and a new block which actually opens new GUI.
This is /fill and similar commands not (re)moving tile entities as they are supposed to.
Also, the reason this glitch resets after restarting the world is because Minecraft tries to validate tile entities when they load and see if their block is still there (which fill doesn't) and destroys them if their block doesn't exist.
It is weird however that /fill does work below 63. This is probably another bug that has to do with chunk update inconsistencies.
Also happens in 18w06a. Gets fixed upon chunk reload. Filling Ender Chests into Enchantment tables also caused the following crash:
[media]
Another thing that happens here is if you replace some written signs with air, the text of the old sign shows up at the gui "edit sign message" where you can enter the text for the sign. You can delete it there but if you leave it, it will show up even after a reload as you've written it.