Error while Promoting a document to its next lifecycle state in WebTop

Scenario: Created a new LifeCycle for a custom object type (inherited from dm_document) using the Documentum Composer and installed it in the repository. Created a new document using the new type and applied the lifecycle to it.

When tried to promote the document to the next lifecycle state, got the following error:
Error in promoting the file [DM_POLICY_E_ERROR_0010]error: "BP transition script error. Details:Error saving the sysobject;[DM_ACL_E_CANT_CREATE_INSTANCE]error:"Cannot create an instance dm_4500000180002505_80000900 of template ACL Approved based on alias set Custom_App.

Reason: The ACL specified in the error message either does not exist or has some issue associated with it.
Solution: Create the ACL and try promoting the document again.

Note: For other possible Documentum (v 5.3) errors visit http://www.dmdeveloper.com/articles/programming/messages53.html