In 38.00, agent has become a subclass of entity. This means that some functions that relied on those types being distinct to disambiguate themselves will no longer compile. For more information, please see the release notes.
We are aware of an issue on islands with Physics activated that can cause the falling animation to activate when jumping on some parts of prefab assets.
We are working on a fix for the next update and will let you know if we have more information.
A recent hot-fix will allow projects with ambiguous identifiers to be opened; however, publishing will still be blocked at this time.
We’re working on a full fix, but it will require Creators to update their scripts to avoid the use of result since it was introduced as a new definition in 38.00.