Sync Problem - MI 2.5
we have a problem with synchronization in the MI. We have a working installation of MI 2.5 SP18 in our test environment. Now, we set up the production environment. At first all went well, I could synchronize from my PC, download installation files etc.
Today I tried to add another device to the environment, and it no longer works: when I do a sync, even from my PC that was working yesterday, then either the sync hangs forever, or I get an "internal server error" without any hint in the trace file.
I can see in the MI WebConsole that a new Device ID is generated every time I try to sync the new device, but the ID is obviously never received by the device.
Any ideas appriciated