We did a upgrade to from 10.3.1 to 11. The upgrade went very well on the
server. But when I deploy the agent update to the clients, it went wrong:

Unable to log into the network because the login credentials or the
server certificate is incorrect"

We can normally log into the Windows network and then comes the Zen
Client. We never had that issue before and all was working very well
with 10.3.1

We have:

One primary server with Windows 2008 (64) (not in Domain, just standalone)
Two Domain controllers
Workstations are Windows 7 (32)
User Source is connected to one DC
We dont use (yet) SSL for credentials from ZCM to the DC

Can someone explain to me what (went) wrong? And how can I fix this
problem ?