Welcome to QuickBooks Community.
Could you please try logging out and then logging back in? You could also try the incognito mode.
In case you still get the same error, please feel free to contact us. One of our experts will help you out.
Thanks for joining this conversation, @agniswan.
You usually encounter this type of error when a problem occurs on your bank's end. It may be possible that your bank's website is undergoing maintenance or server issues.
The period it gets fixed will depend on your financial institution. Most of them resolve the issue within 24 hours.
To check if the connection is back, let's try to manually update your bank in QuickBooks Online (QBO). Here's how:
If the error persists, please proceed with checking your bank or credit card's website. Try to navigate and check if everything is working on their end.
If it's already beyond 48 hours and the problem continues, I highly suggest contacting our Phone Support team to they can open a ticket and investigate this further.
Here's how to reach them:
To learn more about handling bank transactions, check out this article: Manually upload transactions into QuickBooks Online.
Please leave a comment in this thread if you have any other questions or concerns. I'll be here to assist. Have a good one!