It's not possible to sort the workflow tasklist via index values, although the Hotfix 10a or/and HotfixPack 17 for the DocuWare Version 6.7 has been applied.

Please check if you have entered the following key into the file "DocuWare.WorkflowEngine.Srvc.exe.config" (you can find this file in the installation folder of the DocuWare Workflow Engine):

 <add key="DocIndexSort" value ="true"/> 

If not, please add this key to the file and restart the DocuWare Workflow Engine Server afterwards.