Hello @lmbeaudette 

I have an expert taking a look at it, once I found some other people with the same problem, I will post it here once they get back to me.

Thank you for your patience.

I referred to the notice of assessment that I had saved in July and entered that Access code and was denied (31).  I then went to My Account on the CRA website and downloaded the SAME Notice of Assessment which showed a different Access code.  I entered that one and Netfile worked.

Get your Access code from a recently downloaded (most recent) Notice of Assessment.