Hi Wednesday,

I was having a problem with the 8879-S not appearing on the list as well, but just for one client. I had processed an extension for the client but not updated the status. When I updated the status, it then worked just fine. 

So, my suggestion is that if you filed for an extension, be sure that was accepted and updated, then look for the form again. 

It worked for me. Good luck with yours. 

Steve