Event 8 refers to PlayerCharacter[Platform].Speed/20 in a Set Animation Speed action. When you remove the movement, this expression becomes invalid. If you switch back to the event sheet editor, it realises it's invalid and deletes the action. Then, running it works fine. However if you run it without switching it to the event sheet editor, it doesn't check it's still valid, and crashes in the export. That's obviously a bug, but for now you can just delete the action or remove the behavior and switch to the event sheet editor before running.