Happened to me, I pinpointed it to either a struct or data table default value referencing to one of my animation blueprints with a character variable(I’ve tested deleting the character which changes the variable to ‘object’, and replacing the variable type with a duplicate of my character and it started crashing again.)
Duplicating the animation blueprint and deleting the original, then “Manually” replacing the references for it fixed the startup crash for me. Replacing references from the delete popup will result in crashing again.