410000001 
Message
Cannot delete this folder as it still contains sub items. You must empty this folder before deleting it
Diagnosis
In the Menu Structure window (in 
Administration 
System Initialization Menu Structure 
) you have marked a user-created entry, and chosen the Delete button, but this entry
includes at least one sub entry.
Procedure
To delete a user-created entry from the Menu Structure, you have to remove first any sub entries listed under this entry.