Please explain the problem in detail. What happens? What is/are the exact error message(s) ?

Make sure you are not blocking content.

https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop also see https://blog.mozilla.org/security/2021/03/23/introducing-smartblock/

https://support.mozilla.org/en-US/kb/smartblock-enhanced-tracking-protection

Diagnose Firefox issues using Troubleshoot(Safe) Mode {web link}

A small dialog should appear. Click Start In Troubleshoot(Safe) Mode (not Refresh). Is the problem still there?

Many site issues can be caused by corrupt cookies or cache.

Warning ! ! This will log you out of sites you're logged in to. You may also lose any settings for that website.

• Delete cookies to remove the information websites have stored on your computer {web link}

• How to clear the Firefox cache {web link}

I have the same problem. The website accepts my login name and password, but does not respond when I click on the button.

I had been logging into Vanguard for years with little problem, but it sporadically became non-responsive over the last few years. The first time was for a few months. In 2021, it became non-responsive for 12-15 days in the summer, then continually non-responsive since around November, 2021.

I have this problem on my Win7Pro main computer and my Win10Pro laptop.

I do not have the problem with Chrome.

As of 3/16/22, Firefox is again logging in to Vanguard. I have the most recent version (V96.0), installed on the 15th.