Database is not prepared for optimal work for Windows Explorer Client

Behavior:
If you open the Windows Explorer Client the following message oocurs:
"Database is not prepared for optimal work for Windows Explorer Client"

Solution:
To avoid this message you have to enable the option "document name" in the DocuWare Administration for an indexfield for every file cabinet which is used in the Windows Explorer Client. It is important that you choose a field which is not used in the treeview of the windows explorer client.
After this configuration change the message does not occur anymore.