I sent an iMessage (from iPhone) saying File:/// to my iMac and it crashed iMessage on the other end.. and now messages app crashes every time I try to launch!

I sent an iMessage (from iPhone) saying File:/// to my iMac and it crashed iMessage on the other end.. and now messages app crashes every time I try to launch! Also Sent myself an email (from the iPhone) with File:/// as the subject (and in the body for good measure). The Mail.app won't crash on the incoming email, but it won't open that message.