AD Sepulcher loads for Arcane Dimensions. 32-bit TGA files are considered to always have an alpha channel, DarkPlaces often would be the sole Quake engine that did not recognize transparency in some TGA files --- there are many popular image editors that write TGA files slightly differently and some write alpha TGAs in a way DarkPlaces does not handle. Heavily reduced "developer 1" spam of key has "no translation" on Windows.
You made an update here? Nice! I downloaded - keep up the good work :) I just chanced upon your page while browsing here ^_^
-Gem