In the Client - Collaborate tab the Sharing Settings button is showing red, not green.
If I try to add user the client's sharing, I get and error "Invalid Authentication Error:Please confirm the OneDrive admin is authenticated".
In Automation - Apps - OneDrive, a user has been selected as the OneDrive Admin Account to be used (refer to Link your Practice's OneDrive Admin Account) but the selected user has not yet logged into FYI.
The user who has been linked as the OneDrive Admin Account must log into FYI.
Then check again that the Sharing Settings button in the Client - Collaborate tab for any client shows as green.