How Can I Fix Character Inherited Mesh Failure?

I was editing the character jump height one night then decided to undo it with Ctrl+Z and amazingly it managed to bog down the entire engine and caused several save failures. Well now I have it back up but I cannot edit the inherited mesh and so now I’m trying to replace it so when I press Play it doesn’t crash.

What can I do? Maybe even if there is a rollback for saves.