Hi there Mabel_BC,
Thanks for reaching out about issues when logging into your QuickBooks Online. It's a great program able to allow you to access and work on your books from anywhere with an internet connection. I can provide some information about not being able to log in to QuickBooks Online.
There was a known outage earlier today, but the error seems to be resolved. I recommend closing out of the tab, then going back to qbo.ca to log in once more, If the error persists, the next steps I recommend trying would be to do the steps listed below, as the error still being there could be caused by browsing data:
Another thing to beware of is support scams. To reach out to the QuickBooks Online support team outside of the Community, only trust methods outlined by a Community member that has a QuickBooks Team or Moderator badge under their Community username.
If you have any other questions or need further assistance, feel free to reach out here.