Thanks for reaching out to us in the Community. I want to assist you with the error you encounter in QuickBooks Online.
We've received reports from other users concerning this error message from the Capital One bank. However, the investigation status is already showing as resolved since March 14, 2019.
Let's perform some basic troubleshooting to check if the problem continues to persist. If you're unable to download new transactions on a connected account, you can start with running the Manual update feature.
On the left panel, click Banking.
Go to the Banking tab.
Select an account.
Click the Update option in the upper-right corner.
In case you need additional insights, I'm adding the article about manually updating bank accounts:
If it's the first time you attempt to connect, please try to establish a new connection again and make sure you to select the correct bank name or URL. If all fails, I recommend reaching out to our Support Specialists to perform the necessary actions for the error.
Here are the steps:
Click the Help option.
Select Contact us.
Choose a way to connect.
Please let me know if there's anything else I can do for you concerning the bank error. The Community will always have your back.