I got 3x 3CX branches connected, all running V11 SP4 right now. I was wondering if I can update 1 to V12 RC2 and still be able to connect (and chat / etc) with the other V11 branches? It is 'vital' that both ways still work (e.g. the users on V12 will be able to communicate via chat etc to the V11 branches and vice-versa). Otherwise, I rather wait and upgrade them all at the same time - if it was 100% compatible I could run a test at one branch first.