I was playing my worlds in snapshot 20w51a and when 1.16.5 got released I updated my version and went into my world, when I loaded in all my entities were gone. like sheep, villagers, wolfs, and my golems. I don't know how to fix this but I don't want to lose that progress.
MC-212043
Entities not loading
Resolved
Duplicate
0
The appears to be a duplicate of MC-211308, which is caused by downgrading your minecraft version. Please see @unknown's comment on the parent ticket for further details.