Content Server Starts and Stops after an upgrade - No Errors

Behavior:
Content server does not start. Windows Event Viewer shows the following message:

The service cannot be started. The handle is invalid

The .NET error log shows the following: 

Additional information: object_type : Exception event_type : Code location - full exception trace : Error initializing CtS bei DocuWare.Communication.AuthenticationServer.Management.Managers.ContentServerManager.Start() bei DocuWare.Communication.AuthenticationServer.Management.ServerManagement.StartServer() Additional text : 1) Exception Information Exception Type: DocuWare.Communication.AuthenticationServer.ServerStartException Message: Error initializing CtS TargetSite: Void Start() HResult: -2146233088 2) Exception Information Exception Type: System.NullReferenceException Message: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt. TargetSite: DocuWare.DAL.DataAccess.IDataSource GetTaskEngineDataSource() StackTrace: bei DocuWare.ContentServer.ContentServerHandler.GetTaskEngineDataSource() bei DocuWare.ContentServer.ContentServerHandler.get_TaskManager() bei DocuWare.Communication.AuthenticationServer.Management.Managers.ContentServerManager.Start() HResult: -2147467261 Logging Level : CriticalError Message Text : Error initializing CtS Assembly : DocuWare.Communication.AuthenticationServer, Version=6.7.0.0, Culture=neutral, PublicKeyToken=879da714589ba9ea Code location - calling class : ServerManagement Code location - calling method : Boolean StartServer() Computer name : TN-VM Date : 2015.03.26 Time : 08:33:53

Solution:

• Verify that the Content Server's temp folder is correctly specified in the DocuWare Administration and accessible by the service user.
• DocuWare Authetication Server database connection needs to be updated with correct database connection GUID.

*Important: It is a must that you take a back up of the database before making any changes on it. 

To solve this issue do the following:

1. Obtaining the database connection GUID: Run the following SQL script under dwsystem database: 
   SELECT GUID FROM DWSYSTEMSETTINGS WHERE SETTINGS LIKE '%DWSYSTEM%' AND TYPE LIKE '%DATABASECONNECTION%';
2. Check, if the identified GUID is identical to the dcConnectionGuid in the column settings in dwserver table of Authentication Server, if not change the GUID of dbConnectionGuid to the GUID from step 1.
3. The database connection GUID must be same, as in DWAuthenticationServer.exe.settings file.
   The ID can be found in the following part:
   <Connection> 
     <ID>b13378d1-8bd2-46eb-8a25-579f81de9600</ID>
     <Database>dwsystem</Database>
     ...
   </Connection> )
4. Restart Authentication Server
5. Start Content Server