The directory of the game is E:\Jocuri\Quake2 and Quake2.EXE +set game roarke in the command line.
The error :
I don't know what C: represent in this situation. The texture was made with Wally. I don't remember having problems in the past.
Quark settings :
DanielPharos from Quake Army Knife forum is on the path of helping me.
I rotate the coins_2 in Wally (the above image is in Quark texture browser) and made a coins_1.
No problem with this older modified texture when i run the mod.