In a Fabric-based Minecraft snapshot world, I found a consistent collision issue involving villagers, slabs, and a piston/observer setup.
When the setup is activated and a villager is placed inside the enclosed area, the villager sometimes clips through a slab and gets pushed upward or displaced through blocks instead of remaining contained by collision rules.
The behavior is reproducible under the same conditions and appears related to entity collision handling and block update timing in tight enclosed piston-driven spaces involving slabs.
The issue is consistently reproducible and does not appear to depend on entity type variation (tested with adult villagers).
Environment
Minecraft Java Edition Version: 26.2 snapshot 2 (26.2-snapshot-2) Mod loader: Fabric Singleplayer world No additional mods (if true) Tested in Creative mode Issue reproducible in fresh world System: (Windows 10,GPU: NVIDIA GT 1030 2gb,CPU: Intel I5 3740, RAM: 8GB DDR3 )
Attachments
Comments 3
The issue appears to affect zombies, creepers, and villagers, but not skeletons or sheep under the same conditions.
Hi!
Thank you for your report!
However, this issue is Invalid.
Your game, launcher or server is modified.
If you can reproduce the issue in a vanilla environment, please recreate the issue.
Any non-standard client/server/launcher build needs to be taken up with the appropriate team, not Mojang.
A world which had previously been opened with a modified client might be corrupted. Please try reproducing the issue in a newly generated world.
Any plugin issues need to be addressed to the creator of the plugin or resource pack.
If you have problems on large servers like Hypixel, please contact them first as they run modified server software.
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