Welcome to the Community, @user48211.
I appreciate you for trying the troubleshooting steps. Since you're still getting the same error, you can contact our Customer Care team since you're still getting an unusual error while accessing your account.
For future reference, you can read this article with information about adding and managing users in QuickBooks Online: Add and manage users in QuickBooks Online.
Don't hesitate to click the Reply button below if you have questions about accessing QuickBooks Online. I'm always here to help. Have a great day.
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