I tried to follow this article, which said to create a new profile: https://support.mozilla.org/en-US/kb/firefox-wont-start-find-solutions#w_no-error-message

I tried to use this article to make the new profile, but I got stuck on step 3: https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

Does anything happen?

Some problems occur when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

• Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
• Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

You mean like WebRoot? I can't update it because it requires firefox to open in order to do the update. I don't see a list like the one you describe there. That's all I have.

see this answer:

• https://support.mozilla.org/en-US/questions/1198222#answer-1059989

It still doesn't open.

scan your system with:

• https://www.malwarebytes.com/

• https://www.malwarebytes.com/adwcleaner/

• https://www.hitmanpro.com/en-us/hmp.aspx

use malwarebytes in safe mode and normal mode.