That's easy ..................................... well it might be easy to explain if you provided more facts.  As is, I don't really understand what you have going on.

I did an amended NY return for 2018, which I wasn't the original preparer. It was accepted. I tried to do the same thing for a new client in 2019 and the error comes up that the original efile wasn't accepted so I am not able to efile an amended federal. Is there a workaround? Thanks

There isn't any workaround other than to paper file.

thanks Iron Man. 

You betcha!