I’ve found the solution for my project. I’m working on integration Lyra’s character animation logic into a seperate project, which does not base on a Lyra starter project. I don’t use the lyra anim class, but the regular one.
The crash on startup occured because of my animation bp ABP_ItemAnimLayersBase, which is linked over my anim layer interface ALI_ItemAnimLayers to my main anim blueprint. When I removed the file, I was able to start the project again. While the project is running, I was able to paste the file back in from the windows explorer and edit it in UE.
Then I found out that the transition rule between the two pivot states PivotA and PivotB is causing the error. These states are located just in Lyra: ItemAnimLayers → Full Body Pivot State → PivotSM
In this rule there is a property access note calling the function “IsMovingPerpendicularToInitialPivot” from the main animbp. When removing this property access node, the crash issue is solved.
I fixed this in setting a bool variable calling the function in the main anim bp’s threadsafe animation graph and calling the variable instead of the function from ALI_ItemAnimLayers.
No error messages since then, but I’m not there yet where the animation is working properly at all. So I can’t confirm everything is actually set correctly.