Posting this because I searched for the answer before putting in a ticket with OneStream support (who were excellent, by the way).
One of our applications wasn't working in a lower environment. The connection to the application SQL DB wasn't working. Tried removing and adding it back using the OneStream Database Configuration tool.
What the fix was:
The “Invalid Connection” issue was due to the DB security settings for the service account user (that was running the OneStream server application). Not quite sure what the issue was -- it might have been the default schema for the user. In any case, looking at the permissions for the user in the other application SQL databases where it was working correctly gave us the guide towards fixing the issue.
