I can help you log in to your account, root99.
I'd like to verify the specific error message you got when entering your login credentials so I can walk you through the correct steps. Browser-related issues may have caused an unusual response when accessing QuickBooks Online.
We can verify that by logging in through a private browser and ensure to enter the correct User ID and Password. If you're prompted with the error, you can try resetting your User ID or Password. From the sign-in page, you can click I forgot my user ID or Password link. Just make sure that you have access to the email address you'll enter. A reset password link will be sent through it. For more details, you can click here.
If you're able to log in successfully, you can switch back to the main browser and clear the cache. You can also use other browsers to access your account and to isolate unexpected behavior.
You can always mention me in your reply if you have other questions. You take care and have a good one!
