QuickBooks Error 9999 is an online banking error which users encounter when they try to update their banking information. To resolve this issue, you must follow the steps below carefully.
Go to Internet Explorer and press CTRL + SHIFT + DELETE on your keyboard and it will open the Delete Browsing History page.
Now, you must checkmark the boxes against Temporary Internet Files and Website Files.
After that, click on the Delete button.
Hopefully, your query related to QuickBooks Error 9999 is resolved by following the above method. If you still have any more doubt, then contact us at our toll-free number (855)-526-5749.