Random game crash due to loss of an asset?

I didn't even go into warwick's files and somehow one of his assets is missing? wth how is this possible? Even though the team won i still lose a nice 15 LP. When this is finally resolved,another champion asset goes missing, Happened in the loading screen,now the game won't let me back in unless I reinstall it which takes what,15 hours? Does the repair button work on it?