DD version 2.2.2, and Windows 10
Some games were found and can be played, and others not, and I cannot seem to add data files (WAD files I'm assuming), and I don't know why. The image shows what is seen when DD starts. Heretic plays and TNT, Plutonia and Ultimate DOOM seem to play, but none of the others.
I've tried loading the data files, looked through the manual, but there's either no apparent info about it or the data files can't be loaded for whatever reason.