Hey Daniel,
Thanks for reporting this crash. I’ve reproduced the crash and entered it as [UE-35602][1].
I do have a “workaround”, which is actually the way you should do this, even if this crash is resolved. Instead of casting from the AnimGraph, which only has a bool as to whether it’s a valid cast and doesn’t have an isValid? check, you cast from the event graph and define the Mesh Component as a variable. See Below:
Event Graph
Anim Graph
-.