I have actually had this trouble in Powerbuilder 8, 11.5, and now 12.6. It just stops responding and crashes often in debug. I usually remove all the breakpoints and try and only leave the actual one I need at the time. It will proceed but eventually stops responding again. I am currently running with 1 breakpoint. It is crashing, I start it again, it stops at the breakpoint but when I hit to run till it hits again, it crashes. I can delete the OPT file, but it will eventually crash again.
What is triggering the crash that breakpoints need to be removed over and over.