Corridor invoice is rejected with this comment:

Error: One or more validation rules failed. Errors: Duplicate check failed. This invoice is a duplicate of another invoice in the system.

Please contact your client to assist.

Notes: On occasion eCounsel fails to notify Corridor to update the status of the invoice on the Corridor side, so eCounsel will attempt to pick up the same invoice multiple times, which will trigger the duplicate validation rule.  The client should confirm if the invoice is in eCounsel then work with eCounsel Support to make sure the invoice is not re-processed.