Open File/Open Project Breaks!

After using Builder for several months, I am suddenly plagued by a weird
problem.  Selecting
Open File or Open Project does nothing!  I cannot open anything -- even if I
Close All first.   If I use Reopen Project, it works fine.  The problem
won't go away until I exit Builder and restart.  Once it happened the first
time I entered Builder.

I tried uninstall, delete all and re-install to no avail.   Has anyone
experienced this???