E-file Reject due to locked SSN

You'll have to mail it in.

I've had this happen a couple of times in the last 2 years. It is a royal pain when you've already prepared client letters for an electronically filed return and had the surviving spouse or the executor sign the Form 8879, only to have it kicked back on a "filing for a deceased person/locked SSN" error. Now the client letter must be redone for a paper filing, a Form 8948 (Preparer Explanation for Not filing Electronically) must be prepared and you've got to get the surviving spouse or executor back into the office to sign the return and then drag yourself to the post office to mail it certified (because you've been burned before). Not to mention having to explain to the surviving spouse or executor, hey I don't know if this going to go thru or not but we're going to give it a shot and hope for the best. BTW don't waste your time calling ProSeries, they don't have a clue and had no plans to seek a resolution with the IRS when a called several times last year. I don't understand why this is happening out of the blue. I have filed for deceased taxpayers for 15 years and never had an issue until the last 2 years. It makes zero sense. 

"Doesn't offer much solution in the reject other than contact SSA."

In case it is an error, the SSA can issue a letter of explanation and look into the situation.

"Not sure if that means to get them to unlock."

No, you want it to stay locked.