Mobs in general will not walk over short blocks(ones that are shorter than a full blocks, like slabs). This is a pretty easy thing to spot in survival, as lower slabs are used everywhere, so you will typically see mobs stuck on them, not walking over them, or jumping in circles on them.
This does not apply to all blocks that do not have a full hitbox, just a few.
Ones i have tested are: Lower slabs, Enchantment tables, Soul Sand, Brewing stands
This should also affect farmland and path blocks, but those have incorrect(full sized) hitboxes, so are fine in this case.
Keep in mind, mobs not walking over these blocks, is only an issue if the block has nothing below it.
How to reproduce.
1. Go 30 blocks off the ground, and make a 1 wide by 10 long row of lower slabs.
2. spawn a zombie on one end, and a villager a couple blocks away.
3. You will see that neither the zombie, nor the villager will walk away from one another.
4. Start placing full blocks under the lower slabs, and they will start to move again. This can be repeated will all blocks listed above.
Expected result:
Mobs would walk over and pathfind across these blocks with little to no issue.
Below you can see one of my set ups for testing this. Placing solid blocks below any of the short ones, allow the mobs to move.
Full demonstration, and explanation of this bug here:
https://youtu.be/qR5M5v0XDM0?t=172
Related issues
is duplicated by
MCPE-48122
Mobs can't find a path on half slabs
MCPE-51318
path finding
MCPE-53729
ALL mobs can't path on half-slabs, and just spin in circles! (Xbox One&Windows 10)
MCPE-55421
Mobs Continuously Jump When On Non-Full Blocks
MCPE-57128
Mobs Can't Pathfind Over Floating Slabs Or Beds
MCPE-59955
Soulsand prevents zombie pigmen from pathfinding
MCPE-64535
Mob path finding
MCPE-65068
When friendly creatures (cows, sheep, pigs) stand on boxes of boxes, they act as if they are anchored
MCPE-66496
Villagers won't pathfind on bottom half slab platforms
MCPE-67219
Mobs Spin In A Circle/Stand Still When They Are On Soul Sand
MCPE-68444
Passive/Neutral Mob AI breaks upon navigating on top of a chest
MCPE-71806
Mobs walking in circles on soul sand
MCPE-76640
Villagers get stuck on chests
MCPE-77043
Mobs spin on soul sand
MCPE-77621
Mobs Can't Pathfind Onto Soul Sand
MCPE-79857
Mobs get stuck spinning in circles on slabs on a .5 y cord
MCPE-81188
Mobs do not path find over half slabs
MCPE-86791
Villagers not Pathfinding to Beds
MCPE-94949
Normally aggressive mobs towards Villagers will not pathfind to them if either are on a half slab
MCPE-96299
Mobs don't move or attack when they're on top of an End portal frame
MCPE-101871
Villager pathfinding breaks when large numbers of lower half slabs are used
relates to
Attachments
Comments
migrated
migrated
Can confirm to affect 1.12.0.9 Beta. Seems as though they cannot correctly path-find over any block that does not have a (1X1m) collision box (With a few exceptions like top of slabs, thanks to Silent for clearing that up).
migrated
I can verify this affects 1.11.0 at least, and in my case this happened in survival with an enderman freaking out on soul sand.
migrated
I have had this happen. I had used "bottom" slabs as a 2nd floor and wondered why my villagers were not moving, changed for top slabs and they were fine
lillybeacon
Affected in 1.14.0.6
migrated
Affects 1.16.0.53.
migrated
Affects 1.16.0.55.
migrated
Java edition also has this issue MC-157645
migrated
Affects 1.16.0.63
ThatJadon_26
happens with bees under slabs, you have to break the slab above to let it go or it will stay there forever.
GoldenHelmet
In 1.16 the collision box of soul sand was changed to make it a full block, so it is no longer affected by this bug.
migrated
Fixed in 1.16.100.52!!! Finally!
Auldrick
This issue has been fixed in the 1.16.100.52 Beta. The ticket will remain open for tracking until the fix reaches the release version in a future update. No specific date for that can be given.
migrated
Actually, there is still an issue. Mob speed is limited mean a wither skeleton or spider or a fast running mob becomes painfully slow. Do I make a new report?
Auldrick
Yes, please, since this ticket has already been resolved from the developers' point of view. Thank you.
migrated
@@unknown → MCPE-98568.
migrated
Actually guys, this is NOT fixed. The code alteration has had a knock-on effect on other community beloved features, namely, signs and buttons and broke them.
Previously mobs would see signs and buttons as full blocks and would walk over them even if there was nothing below them and now they will not. Please either revert this fix or correct these new issues before this issue gets into the wild as the backlash will undoubtedly be bigger than some of the recent ones as pretty much every mob farm in bedrock relies on one or the other feature (except, perhaps, guardian farms)
Many thanks
a noob
Auldrick
noob1884: This issue is fixed in 1.16.100.52. The knock-on effect is a new issue that needs its own report, even if it might possibly have been caused by this fix (which is something we wouldn't know; the developers will have to figure out if that's the case).
silentwisperer
This bug still affects grind stones, beds, lecterns, stone cutters, chest, daylight sensors, end portal frame, ender chests, bells, unlit campfires. chains, conduits, and end rods. So, every short block not listed in the report 😅 reopen, or new report?
Auldrick
Since the developers have already finished their work order, their ticket for this will be closed. I'm not sure it can be opened again. and in any case it wouldn't be standard procedure for either them or us, so we'd really appreciate it if you could make a new report. Thank you for asking!
silentwisperer
Fair enough, will make a new one. Likely just a copy/paste of this report with updated information about whats currently in the game🙂
silentwisperer
New report. demo of the other issues coming soon MCPE-100622