Upon loading an area, such as returning from nether to over world, or player log out and back in in a LAN game, there is a chance neutral entities in the area disappear permanently.
Edit: including armor stands, this is also an entity. In both instance, it happened during day time, not sure if mobs are removed too.
Environment
Windows 10 Pro, Java 1.8 64 bits
Linked issues
Comments 5
This also occurs if you go to far away: summon armor stand in non spawn chunks, unload the chunk by leaving the area, come back and the armor stand will be gone!
Does MC-65040 describe your issue ?