I’ve edited the topic title as the original was completely erroneous and misleading.
I understand that i wouldn’t use “Proton Bleeding Edge” or “Proton Hotfix”.
This are Beta Branches around Proton Experimental. From the error at the Topic, it looks like that OP had activated this Beta Option. 
But i will keep using “Proton Experimental” (non Beta) because its running for most of the games that i played in the past, just fine.
Anyways, thanks for the link…i wasn’t aware that Proton Exp. has additional options.