You have two weeks to FILE a business return, not e-file.  The IRS shuts down the business e-file soon (1040s are already shut down).

So either e-file before they shut down, or you will need to file by mail.

IRS is not accepting returns. Don't blame Pro Series. 

Is there a particular reason you MUST e-file. You always mail a return to languish in IRS Hell. I would sent Priority mail with tracking. I would not send anything that requires signature on receipt. If any money is due I would direct the client to make an online payment.