Error logging into ITAM 12.9. The server was unable to process the request due to an internal error. For more information about the error, either turn on
IncludeExceptionDetailInFaults (either from ServiceBehaviorAttribute or from the <serviceDebug> configuration behavior) on the server in order to send the exception information back to the client, or turn on tracing as per the Microsoft .NET Framework 3.0 SDK documentation and inspect the server trace logs.
Check the version number of CA.Application.Web.WCF.dll under WCF Service\bin by right clicking the file. Go to Properties - Details.
Open the web.config under the same folder. Check the version for ITAMServiceBehavior. Verify it is the same.
If it is not the same, make a backup of the web.config file, change the version and retest.