Script won't run in Debugging mode won't save

I was repurposing an old script, and was stepping through handlers and everything was working fine, but after an edit and recompile when I hit run with debugging on nothing happened. It was as if there were no run handler. Just a brief pause then the run button was reactivated.

I turned off debugging and it seemed to run fine.

I tried to save the script and got this error.

Cannot save document
invalid component instance (badComponentInstance:-32767)

I pasted the script into a new window and tried again, and same result. Wouldn’t run in debugging but would with debugging off.

Relaunching now.
–> Script Debugger 7.0.9 (7A94)
–> Mac OS 10.11.6 (15G31)

After relaunch script worked just fine in both modes.