Hi, I have the same issue and have checked all of my slips. There is only one box , 042, filled out and the system still flags an error that I have self-employment income. How should I fix this?

@gl0_h   Did you import any information from the previous year? Have you tried deleting the slip and re-entering the slip? 

My issue was related to T3 slips. In one of the drop downs I said YES to the income being communal. Changing that response to NO mostly got rid of the problem. (That also greatly reduced my refund.) Unfortunately I had also completed the Fiscal Year parameters when trying to troubleshoot. I couldn't get rid of the Fiscal Year error. I ended up redoing the entire return from scratch. I hope this helps

I think I found the bug !!!   Had a T3 and inserted information in the Foreign income box (which I later deleted that information).  But I had put down source of Foreign income as "USA" (assumed this was for a US ETF.  Anyways, the fact that there is a Foreign Income "USA" noted, seems to trigger all of the self-employment/business income nonsense.   When I reset the "source of foreign income" drop down, to nil, then I could immediately file via NETfile.   An obvious bug in the software.