Your reputation of tool-breaker / bug-finder is kindofa public secret around these forums 
And that's not the only reputation I have round here!

The actual fix is that I create the (mandatory) '<no group>' treeview item, when you start a new Configuration using File/New. Creating a new group won't help you either, as you prolly have found out by now...
Indeed I have.
So, I decided to take a copy of Winbuttons.ini and delete from that everything but the first button, then go from there.
Part of the way through the deletion process I got this:
Line 1325 (of winbuttons.exe on my system)
Error: Array variable subscript badly formatted
Also, I tried:
file/new
then without doing anything
File save (as MyTest.ini)
That doesn't seem to want to save.
Before long I may
have to read something!
Are we having fun yet? Just pray that you find no other users with my skill(?!) set.