unable to open a website

When were you able to log in successfully the last time? Does the banking appear to be pretty much the same, or did the appearance change if you can remember? It might be a compatibility issue (they have a new version that breaks something), it might be a security issue (stale data, not logging you due to VPN or some anti-virus/anti-malware protection etc.) — ideally you'd want to first try logging in via a new Private Window tab, to see if there's any difference. The longer steps are e.g. in previous threads: https://support.mozilla.org/questions/1582595#answer-1819633 If you post which bank that is folks can look up any known issue, and if you're on that page where you're stuck you can also report [[How do I report a broken site in Firefox desktop?]]