Diagnosis
You want to assign a revision level for a material or document.However, the revision level does not exist in engineering changemanagement Customizing (Revision Levelsactivity).
External number assignment is not allowed, as the Ext. revisionlevel indicator is not set in the
Set up control data activity.

System Response
The system does not allow the revision level assignment.

Procedure
You can only assign a revision level which is defined for theappropriate object (such as material) in settings in Customizing.
If you want to assign this particular revision level, you need to addit to the settings in Customizing.