In my critical diagnostics, it shows that the EFIN was not initialized and that it should be 6 digits. I did not understand what this meant. Could you help me with this?

[Just-Lisa-Now-]

Do you have an EFIN?   Its a 6 digit number issued to you by IRS that allows you to Efile a tax return.

[itonewbie]

Is the F.8879 showing your correct EFIN?  If not, have you checked that your Intuit account has the correct EFIN?

[IRonMaN]

Square 1 - Is this the first return that you have tried e-filing?