Crashing when linking anim layers for first time?

Keep getting this crash, seems common but not sure what’s causing it exactly. I know its related to linking new anim layers for the first time and only happens like 50% of the time. I think its to do with property access nodes based on the “PropertyAccess.cpp” bit but not sure what I’ve done wrong with them.

Any ideas?

Assertion failed: Indirection.Function->GetReturnProperty() [File:D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\PropertyAccess.cpp] [Line: 526]