I'm not sure if this is a bug or a feature, but the handy "TextDiff" dropbox that pops up in the upper right when you drag a new file over PSPad only seems to appear if the Code Explorer Window is visible (Ctrl+Shift+E).
I can't find it documented anywhere... so maybe this question at least will provide a clue if anyone else is trying to find out where it went. That dropbox popup is one of my favorite things about PSPad, BTW. -- <https://forum.pspad.com/read.php?2,72285,72285> PSPad freeware editor https://www.pspad.com
