Normally, if you use non-gui macro "Convert clip to fax" or "convert clip to frz" without the clip, the script will give you a message that there is a missing clip on the line. However, if you hotkey said macros and press the hotkey fast enough (without the clip on the line), the message doesn't appear and it results in a crash. Happens 100% of the time. I'm on build r8903.