FF Portable 115.4.0esr (but also going back to at least 115.x.x if not older versions) Win7SP1 x64
For various purposes, I used to drag 'n drop shortcuts from FF URL bar, into folders. That stopped working after a FF update. Researching it, I found it worked again by launching FF portable with -no-deelevate on the shortcut to it.
That worked for (months?) and then after another update, could no longer drag and drop shortcuts into folders again. Researched it some more and found this could happen if Windows UAC was disabled, which I had done on this old system because it was interfering with a lot of older apps running correctly.
Enabled UAC, and could once again drag and drop shortcuts from FF URL bar to folders, but as expected, UAC then caused too many problems for apps. Decided I could more easily live without drag and dropping shortcuts so I disabled UAC, and rebooted... and now I can still drag and drop shortcuts to folders.
It doesn't make sense. Toggling UAC on and then off again, (rebooting both times) fixed dragging and dropping shortcuts into folders. Any idea why, what the underlying issue was?
You'd have better luck asking the Firefox folks as this isn't related to the portable version. Additionally, we neither test nor support any of our apps with UAC disabled.
Sometimes, the impossible can become possible, if you're awesome!
Fast Forward to today, the same firefox portable installation had updated itself a few times, now at 115.10.0esr. All this time, it has worked to drag-drop shortcuts to a windows folder, or to other applications.
Suddenly today, dragging them stopped working again. No idea why, AFAIK FF portable had not just updated itself today to a newer version, as I always notice that. It just stopped working to drag and drop and all I needed to do was close and open Firefox again. UAC still disabled, didn't touch that.