Environment
 Novell eDirectory 8.8 for All Platforms
Novell eDirectory 8.7.3 for All Platforms
Novell iManager 2.7
  
Novell eDirectory 8.7.3 for All Platforms
Novell iManager 2.7
Situation
 Error -644 in iManager when trying to remove an attribute formerly used by an auxiliary class.
  
Resolution
 Check eDirectory synchronization. In this case the attribute was still used by an object which did not sychronize correctly. Fixing the synchronization problems allowed removing the attribute.