Regions Bank connection suddenly stopped working

Have you tried to open your QBO account on private/incognito browser?

Did not work, just tried it. 

Thank you for the suggestion though.

Thanks for the clarification, @wshuler.

I also appreciate you for performing some troubleshooting steps to connect your Regions Bank account.

I can provide you some insights on how to get around this issue. I recommend downloading your bank transactions and upload them into your account. Let me show you how.

1. Sign in to your bank’s website and follow your bank’s steps to download your transactions as a CSV file.
2. Follow any on-screen instructions to finish the download.
3. Once done, sign in to your QuickBooks Self-Employed (QBSE) account.
4. Go to the Gear icon and select Imports.
5. Select Import older transactions for the account you want to add transactions to.
6. Click Browse and find the file you downloaded from your bank.
7. Select the file and click Open to start the import.
8. Review the column headers and data.
9. Click Continue to complete the import.

You can also see this link for more details: Add older transactions to QuickBooks Self-Employed.

I also recommend contacting the Regions Bank support team and verify of any updates or issues on their end. Once you're all set, categorize your transactions on the correct line of your Schedule C for accurate tracking.

Keep me posted if you need further assistance managing your transactions. I'm always around to help you. Have a good one!

@wshuler 

Utilize the trial version of SlickConnect to isolate the issue. If the same error persists, the problem is on your bank.

https://www.moneythumb.com/?ref=110