For some reason a site is connected to a content database that does not exist anymore. Probably someone experimented on that site in the past, the sysadmins moved all SharePoint db's to a new server and nobody thought about updating the existing database that was not (not really) in use.
Now I'm stuck with a mapping to a database that does not exist. How can I fix this. I've tried the DetachDatabase command but that needs a connection to the database. And that server does not exist anymore.
Solved! Go to Solution.
Please review "View Database Mappings" not reflecting the correct mappings after changing them. Read all of it before making changes, but it may help in your case. It reviews how to change the mappings as well as how to reset if a mapping goes to the wrong database.
The conclusion states: To resolve this issue simply deactivate and reactivate the "Nintex Workflow 20XX" feature at the site collection level. This will update the database mappings in SQL as it will query your Nintex Workflow Config database to find out what Nintex Content database is mapped to the Sharepoint content database the site collection is using and update the record (or create it if it doesn't exist) in the dbo.Storage table.