I'm having essentially the same problem. I got a "license warning" and the SOA lost all connections to the workstations.
I tried reinserting the license a few times. See my post here, "LicenseUtil.exe Windows Exception Code 0xc0000409" (
http://forum.avast.com/index.php?topic=130184.0).
My reseller arranged for Avast to issue a new license to me. I put that license on the server desktop and used the Insert License procedure. It failed, even after a reboot.
After getting no help for that, I poked around some more and discovered:
The ORIGINAL license file was not in the location where I had saved it when I originally installed it.
The "licence file location" setting in Admin>Settings>Advanced Settings in the SOA had not been updated. It still showed the original license file in the original location.
I've tried reinserting the old license, and then reinserting the new license, several times. In all cases the system remains in "Waiting for Trial" status, and the "licence file location" setting does not change. I've tried changing that setting manually to point to the new license in the proper location. That has no effect.
I am getting no help with any of my problems from Avast! staff, and only scant notice from the reseller. This is incredibly frustrating.