If you just download GARbro-mod and insert the newest Formats.dat, the program will not work. Moreover, if you move this file to a regular GARbro, for some reason no new formats will appear and the application will continue to work as usual.
What confuses me is that in GARbro-mod there is only 1 file in the GameData folder. Maybe that's why the application doesn't work? It seems rather strange.
Honestly, I don't understand what strange problems I'm having and why the hell Formats.dat does NOT change the old GARbro, even though it should. Same thing, by the way, with other versions of GARbro-mod: I tried to download even the very first one, but it still doesn't recognize even unencrypted .xp3-format. I'll try it on another computer, but I have a bad feeling about it....