Support said i have to go down 1 version to SR3 but I dont want to do that since SR4 release notes said that it actually fixed a lot of performance issues and i dont have time to retest everything.
What i did was restart services to clear all hanging sessions then i tweaked CPU affinitly. I also unchecked "Allow Only One Copy of Document in Memory" hoping it helps. Reduced Timeout settings hoping that it releases any future locked sessions sooner.
So far no more hanging sessions but i do have more "reconnecting" sessions, possibly because i have more users now than before.
I had the same issue. Could not share a session (Could click on the Start Sharing button but nothing happened)
In QMC > Status > QVS Statistics I had a number of supposedly active sessions. However if I looked in the Server Performance log there where no active sessions. So I restarted the QVS and could then share a session.
I was running QVS11.2 SR4 which I have now upgraded to SR5 so will wait and see if the issue reoccurs.