How do I fix the ‘untrusted certificate’ error when logging into my bank’s website through Banktivity?

To get around this error you will need to hold Shift when you open the software. This will prevent the page from loading right away and you can click on an account. The certificate issue itself will need to be reported to the bank so that they can update the certificate that is failing. In the meantime you will need to download the account using Safari or another external browser.