Find and Change when stepping forces force quit

I was step debugging a script when I made a goof.

I tried to do a find/change without stopping the script.

In that case I expected to get a dialog asking if I wanted to stop the script or cancel.

Well, I got that dialog, but then the interface began “blinking” about twice a second and the dialog buttons didn’t work, and I couldn’t cancel and the spinning rainbow hang cursor appeared.

Only way out was to force quit.

–> Script Debugger 7.0.12 (7A112)
–> Mac OS 10.13.6 (17G13035)