I just tried e-filing 2024 federal and state returns for a client whose return I prepared for 2023. Inexplicably, I received an E-file Transmission Failure message:

"A return with the same SSN or EIN has previously been submitted. If you need help resolving, please contact customer support.

Problem occurred transmitting efile data".

I have no idea why I would get this message the first time I try to e-file the 2024 returns. Has anyone been able to solve this type of error message?