Thank you for taking the time to visit the Community to post your issue, although I apologize that you haven't received a response.
If the usual troubleshooting steps for the OL-393 error do not work to correct the error, then you will need to contact your financial institution for assistance. Quicken does not have access to the financial institution's servers to be able to correct the problem.
This may require you to request to speak with an online services specialist that handles transaction download issues at the financial institution. If your financial institution states they can't assist, an escalation with them may be necessary.