It’s a script error. ¬†You must report it to QuickBooks.

See below.

https://community.intuit.com/questions/1640087-banking-error-9999-from-wells-fargo-this-has-been-goi…

Resolution for '9999 bank doesn issue: 'Chase error 9999 bank doesn’t update' available: Yes.

The 9999 bank doesn issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the 9999 bank doesn issue yourself by looking for a resolution described in the article. If it is a complex 9999 bank doesn issue or you are unable to solve the issue, you may contact us by clicking here or by using other 9999 bank doesn support options.

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