I'm having the same issue. I wonder if too many people are trying to file at once.

I just did my fourth try and it worked. 

@user763543785 , thanks for the update, and we're glad you were able to Netfile. 

@user17776049878 , you're not the only one. It is very likely because of the last-minute rush on April 30. When the CRA's systems are too busy to handle all the work, a lot of people get the "Result Code 0."Sadly, TurboTax can't fix this error code. You have to keep going. We also suggest that you check a few things because a lot of people make the mistake of saying "Yes" when asked, "Is this your first time filing a return with NETFILE?" If you have filed before, make sure this is "No."

 You don't need to enter a Netfile Access Code (NAC) from your last Notice of Assessment, so you might want to try taking it out.

You are correct—CRA went down for a few hours because of the overload.  🙂 I hope you were all able to successfully file your returns.