Hello @liberodark, please add PROTON_LOG=1 %command% to the game's launch options and drag and drop the generated $HOME/steam-$APPID.log into the comment box.
Yep try this :D thx
PROTON_LOG=1 %command% = https://pastebin.com/PuB8wxsx
err:module:import_dll Library mfc100.dll (which is needed by L"Z:\\home\\pc\\.local\\share\\Steam\\steamapps\\common\\Isomer\\AppLauncher.exe") not found looks like the line of interest from the log.
Distro: Manjaro XFCE 17.1.12
GPU: GTX 1060, Nvidia proprietary driver 396.54
Resolution: 1920x1080
RAM: 8GB
Proton 3.7-5 Beta