Error in Workflow when confirming more than one task

I get an error in Workflow when confirming more than one task in Monitor Tasks window; "2 Documents could not be confirmed". The tasks can be confirmed one at a time. They are all of the same workflow version. 

Are there any other requisites need to accomplish a multiple confirmation?

Thanks,

Dear Steve Shriver! It looks like the Community cannot answer your question. Thats why we have opened a Support Request with the Number SR-112618-F7J9D for you. A Software Support Specialist will contact you directly to follow up. We will update this thread with the solution as soon as we have solved the Support Request. With Best Regards, DocuWare Support Team