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}

This can happen if you have disabled all three setting for searching via the location/address bar.

The location bar drop-down list can show history items, bookmarked pages, pages opened in tabs, and search suggestions. You can set what suggestions show When you enter an URL in the location/address bar bar via Options/Preferences -> Privacy & Security

• Address Bar: When using the location bar, suggest:
  History
  Bookmarks
  Open tabs