Also, upon convertdata popping up, if it can't convert the file, I get the generic error saying that convertdata has stopped working, and the editor displays a blank box where the lines normally are.
I know about that problem. I will not fix issues that are due to third party programs, such as convertdata.exe. The solution is to open entity files that are in the proper text or binary format.
It lets you open the DefEditor, the Dekhranic tools, and the about me while opening/closing files and closing the program. The about me pauses opening/closing, though the others do not.
Yeah, this is by design. I thought it would be nice to let the user mess around with some stuff while waiting for a bunch of files to open. The about box is a dialog, which means that it swallows events over the main form. The other things are third party programs, which are separate from my program. If you can show that this somehow causes a crash (not by doing something stupid like editing stuff while opening a ton of files), then I will figure out a way to fix that.