ETS 2 MP Launcher "Unspported Game Version" Error

[DownhillRider]

Hello guys 

Im getting "Unspported Game Version" Error when I open the launcher but  I tryed this steam beta acces (temporary etc.) but its still getting error I downloaded 1.21.x temporary version still same but when I join the game "ETS 2 SP" my game version it seems 1.21.4s how can I solve this problem ? 
Anybody have previous mp launcher ? 

[Guest]

Before opting out. Make sure you're on the version supported by multiplayer. Once you've downgraded. Then opt out of betas. If it still doesn't work. Go to your downloads, delete all the .rar files for ets2mp and go to the website and redownload ets2mp

[[Q-LOG] gibon]

Hi! You need to select "NONE - Opt out of all beta programs"

[DownhillRider]

Same

[El1teZombiezHD]

Best answer chosen, Locked and Moved to Solved.