Hi Steve,
just released a new version of my GuiTools Framework.
Before I release things, I usually check if they properly compile in the historical SDL 0.954 version and the latest stable new GL versions of QB64 (both, 32/64 bits).
This time I added your SDL 2020 updated version from your repo in my testing chain for the 1st time and found that the IDE will crash after a few seconds when syntax checking any loaded GuiTools application (from the src_XXX folders). As far as I could find out, it must be some recursion bug in the $INCLUDE handling, because if I paste the include's contents into the sources (in place of the $INCLUDE lines) to put everything together in one big file, then it works fine and the programs will also properly compile.
Maybe you can have a look at this, if your time allows, no need to hurry...
I'll dig into the issue in a couple of weeks, since it doesn't seem to be a rush problem. :)
For now, I'm still swamped with getting everything transferred over to the new PC from the old one, and I'm working on upgrading and debugging the SaveImage library. After that, I'm going to try and spend a few weeks to catch up on what I've missed on the forums and maybe see about sorting out the current version of the perpetual CONST glitch which plagues us.. SDL-2000 should be on the list of things to do after that, and I'll try and sort out what's off with the $INCLUDEs at the same time I add in the precompiler $IF support for us. :)