Here is a problem we found with the SalesLogix 7.2 Web client. After logging in, the login screen goes away but an error message is thrown before any other screen appears. What caused this was the UserNotification table contained a record that pointed to a non-existent Activity record. Somehow the Activity record got deleted without the UserNotification entry being deleted. The cause of the orphan records is unknown. The solution was to verify the existence of orphaned UserNotification records and then delete them. These scripts seemed to work well.
Select * from sysdba.usernotification where
sysdba.usernotification.activity id not in (select activityid from sysdba.activity)
Delete from sysdba.usernotification where
sysdba.usernotification.activityid not in (select activityid from sysdba.activity)