When online banking accounts cannot be accessed by the software, QuickBooks Error Code 9999 appears. This is usually the result of a problem with the bank server, an internet connection, or erroneous login information. In order to fix this issue, you must confirm bank information, check network connectivity, and make sure QuickBooks is up to date for seamless synchronization. Furthermore, our QuickBooks Experts Team can be reached by phone at 1.855.738.2784.