Castle.ActiveRecord.Framework.ActiveRecordException: Could not perform Delete for XXX —> NHibernate.Exceptions.GenericADOException: could not delete collection | Blinded by the lights
The beginning of the stack trace I got today looked as below: 2009-05-19 11:01:45,078 ERROR [5232] XXX – Speaker already deleted: Castle.ActiveRecord.Framework.ActiveRecordException: Could not perform Delete for Speaker —> NHibernate.Exceptions.GenericADOException: could not delete collection: [XXX#XXX][SQL: SQL not available] —> System.Data.SqlClient.SqlException: Cannot insert the value NULL into column ‘SpeakerId’, table ‘XXX.dbo.lnk_Session_Speaker’; column does not allow nulls….