Looks like I spoke too soon.

Apparently on at least one system the update was causing applications to disappear from the taskbar when minimized.

The cause was a combination of my decision to use an Event Hook to detect the cloaking and uncloaking of UWP apps (rather than polling for it every 5 seconds) together with passing that information to the subclass proc of the main window (which among other things also deals with shell notifications) so it would process that event.

What I forgot to notice was that passing it a NULL window handle could cause serious problems, as the events "passed through" and it tried to call the original window proc using a NULL window handle (EDIT: just had another look at the code and the only reason it didn't crash is because I actually have a fail safe that passes control to a Dummy window Proc if you pass it a NULL window handle or a NULL proc address - but in that case, why the issues the user experienced?!).

In truth the WHOLE THING should have crashed the second it tried to do that (and that would have been a good thing since it would have allowed me to detect something was wrong with that code before the official release) but what ended up happening for God knows why is that HERE it gives me no problems whatsoever (even on my Windows 10 VMs) but at least on ONE particular system it was causing some very weird behavior such as window buttons disappearing from the taskbar when minimized.

It was pure luck that I noticed the issue in the Uninstall Survey, the person left an email address, and I decided to reply to them asking what was wrong. The person in question was also very willing to work with me in detecting the cause and because of this and the fact that the problem started immediately after running Nexus, zeroing in on the guilty code and fixing it was actually pretty fast.

I already updated all the files in the Winstep web site with fixed versions, but not knowing how many people are affected by this is killing me. The vast majority are so used to unresponsive companies that they won't even bother sending an email to support. They either uninstall or go back to the previous version - and that is a tragedy, as not only are they not helping themselves, as they are also letting other suffer from the same issue.

Anyway, now I have to make a decision on whether to re-release the update or not. As I pointed out in a previous post, many users get REALLY upset if they have to download a multiple megabyte update more than once in a very short term.