Citrix Xen server help. I get constant disconnects of the citrix xen server

Hi, I have a Citrix Xen server 6.5 which was running fine. Yesterday Time sync between the host and VM's got disrupted and now I can login to the xencenter to view or edit things but I get disconnected very soon. Then I can press reconnect all is okay. 10 seconds later disconnectd. Who can help? Also maybe I need to install some updates. Maybe you can assist to? And I might need to shift some disk space from 1 VM to another VM