Vanilla Dnn 7.3.4.
Adding Digital Asset Management (File Manager) to an empty page.
Settings - Digital Asset Management Settings.
Set "Mode" to "Group" and click "Update".

Result:
"The group ID is not set. Please go back to the groups page and select the desired group."

But there are no more settings or options to select from?!

"Funny" thing is when I searched for this error I found this address with the very same issue seen live:
http://www.dnnsoftware.com/community/group/docs

Any suggestions?
Cheers
Mikael