Debug in spyder

Spyder 5.1.5 in anaconda… suddenly unable to run debug. Console locks up when debug is started on any script. scripts run perfectly in spyder if not debugging. If I install spyder 5.2.2 outside of anaconda, debug runs perfectly.
HAve installed and reinstalled anaconda with no improvement. Debug looks OK in console initially but cntrl F10 does nothing and console shows message: --“KeyboardInterrupt–
For copying text while debugging, use Ctrl+Shift+C”
when I click on “stop current command”