It is being caused by a QBs script error. You will need to report to QBs for them to notify you when it is fixed.

Check out this post:

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

Resolution for 'being caused issue: 'Our bank recently underwent a computer system upgrade and my accounts are not automatically updating and I can’t manually update them either. Please help.' available: Yes.

The being caused 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 being caused issue yourself by looking for a resolution described in the article. If it is a complex being caused issue or you are unable to solve the issue, you may contact us by clicking here or by using other being caused support options.

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