Thanks for choosing QuickBooks Desktop for running your business, jamesw665. It's my top priority for you to connect your bank account for Online banking.
We haven't received any reported case about the banking error 301. This is a communication issue between your bank and QuickBooks, or company file. It could be also your account info changed or your financial institution hasn't turned on a service.
To better isolate this one, let's create a test company file to determine if the error is caused by your bank or something in the software.
If the same thing happens, there’s a problem with the connection from your bank. Just log in to your bank account on a browser, then check if you have any bank security notification. If there’s none, please reach out to your bank.
If you don't encounter the same error, the problem is in QuickBooks. To troubleshoot this one, proceed to Step 2 until Step 5 in this article: Get help with error OL 301 or 393.
I'm just one reply away if you need a hand with matching and categorizing the bank transactions or any QuickBooks related. I'm glad to help.