according to your picture this is more a SystemLink TDM question than a DIAdem related issue.
Nevertheless, the first thing I would try is to check the configuration of the "SystemLink TDM User Account"
in the "NI SystemLink TDM Configuration" utilty (can be found in the windows start menu).
There you can define the account and its password. Requirements for this account are mentioned there.
After that you have to create an own datafinder server instance, otherwise you get just shown the standard "FileIndex".
How this is done, you can find here: https://www.ni.com/docs/en-US/bundle/systemlink/page/creating-configuring-data-indexing.html
first thing is to restart the complete server. If this does not help, then follow the steps below.