Can't create folder portals anymore

I can't create portals anymore.  Fences crashes and it restarts after freezing for 20 seconds but the portal hasn't been created.
I re-installed several times.  At first this happened trying to access a folder one level up in an existing portal.
Any ideas?

Running Fences 3 on Windows 8.1.  Working fine for many years ....
Thanks

UPDATE: This is the most bizarre thing I ever encounter ...  The crash ONLY happens with one folder named "Design".  If I rename it to something else, Fences works fine, no problem creating a portal there or with any other folder.
I checked several times .... what is magic about the name "Design"  (apart from Design being a great thing ...)