SAP Message REB_GENERATOR309 - Deletion was prevented by an object

Diagnosis
Deletion was prevented by an object.
Deletion cannot be performed at present. Owners of objects to be deletedcan register in the generation process and prevent the deletion frombeing performed for certain system constellations.

System Response
The selected action cannot be performed.

Procedure
Information only. A detailed description of the problem is providedfurther above in the log. A message from the owner of the object thatprevented the deletion should also be displayed. If this message doesnot exist, contact your support organization.

Procedure for System Administration
Transfer the system to a status in which the generation can beperformed. If a transport request import failed, import the requestagain.