Enterprise server is normally just audit log,

Only SolidCP server actually supposed to push errors to a SolidCP event log section by default.

Okay. Tried running the powershell stuff on the exchange server as well and it installed a bunch of stuff but didn't fix the problem. A iisreset didn't help either.

Spoke to a friend of mine who is a .NET developer, and he mentioned that the System.String[] part might just be because of the way it is being written to the log since it uses the .toString method. But if it is written correctly on a working install then the problem is narrowed down a bit.

I tried to do some packet sniffing on the servers to see if I could catch the traffic and see exactly what goes on, but it seems like most of the data is sent binary :/

Alright, managed to get a debug version of the SolidCP server running on the Exchange server and attached a remote debugger to it.

The value of the variable oabVirtualDirs is "HOSTINGEXCH01OAB (Default Web Site)" and of the type string.

The following screenshot shows the full parameter object-thingy:

Does that seem right to you?

Huh.. When running the debug version of the SolidCP server on the Exchange server it actually works.. Just pulled the newest one from Git..

Gotta try and see if I can make it fail now while having the debugger attached.

Got the same error! Check the server-configuration inside solidcp of the exchange server. Active Directory Settings need to be set to "Use Active Directory Accounts", Root-Domain need to be set!