Nintex Workflow 2010 issue: Error establishing database connection. SQL Error: 515 VALUE NULL

Today I came across an issue at one or our clients where Nintex Workflow 2010 was up/downgraded. After starting a workflow it threw an correlation ID. After looking up this error in ULS Logging I could find the error message described below:

Error establishing database connection. SQL Error: 515.: System.Data.SqlClient.SqlException: Cannot insert the value NULL into column ‘DatabaseID’, table ‘DEV_Nintex_Workflow4.3.3.dbo.Storage’; column does not allow nulls. INSERT fails.  The statement has been terminated.  at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)   

 at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)    at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)    at System.Data.SqlClient.SqlDataReader.ConsumeMetaData()    at System.Data.SqlClient.SqlDataReader.get_MetaData()    at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)    at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)    at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)    at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)    at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)    at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior)    at Nintex.Workflow.Administration.Database.ExecuteReader(SqlCommand command, CommandBehavior behavior) (Build:2330)

The resolution for this issue is related to either a missing Config or Content Database for Nintex. If you look within Central Admin, you actually have to specify the database to use TWICE. This is due to the fact that Nintex has a “Config” and “Content” database – mostly (usually) within the same SQL database.