You'll see the following error message in H&R Block’s 2016 tax software if you have entered income or expenses on your return from more than six business activities:

You can't file this return online using NETFILE because you entered income or expenses from more than 6 businesses (on the T2125, T2042, T2121, T5013, T777, TL2, or T776 page). Don't worry, you can still file it by mail. When you get to the File page, you can download and print all the forms you need to mail to the government. [error code: 264] 

How do I fix this?

If you’re entering more than six financial statements from business activities (such as the the T2125, T2042, T2121, T5013, T777, TL2, or T776 forms) on your 2016 return, you won’t be able to NETFILE your return with H&R Block’s tax software; the Canada Revenue Agency (CRA) requires the return to be filed by mail. You can download and print a mail-in version of your return on the FILE tab. Simply select By Mail in response to the question, How do you want to send your 2016 return(s) to the government?, and click the Mail-in Version button next to your return to download it.