The word "Old" in that financial institution name displayed in Quicken should indicate that this is an outdated presence. This is typically displayed when that FI has changed their services, service provider, or other major change on their server-side.
I suspect that the FI name you should be using in Quicken is M&T Bank Direct Connect:
When an FI makes a change like this, it's possible that Invalid Login messaging would be returned when attempting to connect to the presence that they're disconnecting (or have already discontinued).
Edit your account, Deactivate for online services, then Setup again but select the Direct Connect option during the reactivation.
In Quicken Windows, this is on the Online Services tab of Edit Account. In Quicken Mac, this is on the Troubleshooting tab of Account Settings.