Diagnosis
The subscreen area with the specified name is not referenced by anyother tab title.

System Response
The existing reference remains unchanged.

Procedure
Check the names of the subscreen areas that are assigned to the othertab titles, and enter one of their names.
Note: Each tab title must have a subscreen area assigned to it. Thisassignment is automatic when you create a subscreen area within a tabpage. However, you can also assign one subscreen to more than one tabpage by entering its name in the "Reference field" attribute of therelevant tab titles.