Issue
When viewing, in Central Administration, the Nintex Content database mapping settings in Nintex Administration, the following error might occur:
Nintex Content Database was not found.
Nintex Content Database was not found.
Resolution
Identify the database name which is deleted from the databases table.
Select * from dbo.databases.
Get the DatabaseID
Select * from dbo.storage where Databaseid = 'DBID'
If you find any, Run the delete command
delete from dbo.storage where Databaseid = 'DBID'