Same thing happened to me last night after years of successfully using Turbotax. TT said fix the error and resubmit. However it was because of missing IPPIN number which I never heard of. Looked at IRS online and said could take up to 21 days to get the info. There are two options: one is to send a paper return and supporting documents or file for an extension. I'm filing for an extension but I will do that by printing and sending the paper Form 4868 for an extension. I don't trust filing it online as it might be rejected too and today is the 15th.