InfoPath 5337 error

Error: 04/01/2013 08:43:41.45  w3wp.exe (0x0C78)        0x229C  InfoPath Forms Services               Runtime – Business Logic              7tge                Medium               Exception thrown from business logic event listener: System.NullReferenceException: Object reference not set to an instance of an object.     at Microsoft.Office.InfoPath.Server.SolutionLifetime.XmlEventExternal.<>c__DisplayClass10.<add_Changed>b__c(Object sender, XmlEventArgs e)     at Microsoft.Office.InfoPath.Server.SolutionLifetime.XmlEventExternal.<>c__DisplayClass20.<FireChangedEvent>b__1c()     at Microsoft.Office.InfoPath.Server.DocumentLifetime.OMExceptionManager.CallFormCodeWithExceptionHandling(UserMessages userMessages, OMCall d)            0ba576c2-222a-4d18-bc06-7fab0ce977a1

Pointers:

1)      Check for unwanted change events

2)      Check for unwanted data connections

3)      Check for unwanted fields on the form

Resolution:

I was able to fix the issue by deleting the changed event under FormCode.cs (an extra event that got created when I accidentally double-clicked on a field on the form).