For the longest time the 363 was glitched: although it was Livery Designer compatible, there was no way to select any livery (save the default) in timetable mode. Then it was fixed. But now - possibly due to the introduction of the DBB Blue version with Dresden - it's bugged again. No livery-selection option at all, and my alternate paintjobs are unusable again.
I just checked on my side, I see my different liveries for the BR 363. Would your UGCLiveries_0.sav file be corrupted? If you are using the "TSW2 Livrery Manager" program, this has already happened to me when I deleted a livery.
As it stands, all of them are accessible in Livery Designer; but in a route's Timetable menu, none appear (and the 363 has no pink-paintbrush "livery" button). All right, how do I generate a clean file? I suspect this may have been what happened; with the advent of DRA with its DBB blue version, I deleted my homemade one and that might have caused the issue.
If you are using the "TSW2 Livrery Manager" program in version 0.4 or higher, in your directory "\Documents\My Games\TrainSimWorld2\Saved\SaveGames\". There are backup files called UGCLiveries_0.sav_YYMMDD-HHHHHH.bak. You just have to rename the backup you are interested in as UGCLiveries_0.sav.
No dice. I've rolled it back to a pre-Rush Hour backup, restored my Livery Manager backup file (which does have it them in there)-- and nada. Also, all alt-liveries for the ICE3 (both models) have also vanished. Has DB pulled some licensing stuff on us? But then, none of my other German stuff is affected. OTOH, those are the two locos for which I seem to recall deleting liveries from inside Livery Designer, rather than via LM. Maybe that screwed something up? Should I just delete the .sav file, not rename a backup, and let the game make a vanilla one from scratch?
Nothing seems to work. Creating new liveries for those trains also doesn't work; just the default with no options.
Yes, delete the original .sav file. TSW will recreate a new one. For me, no problem to create new deliveries for ICE 3. Maybe do a file integrity check of the game, via Steam.