<Control> F opens the Find box, and a second <Control> F closes it.

You can only use Ctrl+F to close the find bar if you have an extension that supports this feature. Otherwise you should be able to close the search bar with the ESC key.

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
• Do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

The System Details list next to the question shows that you run an older Firefox 50.1.0 version that is no longer supported with security updates. Always update Firefox and Add-ons to the latest versions to get all security fixes.

Please update to the current Firefox 51.0.1 release.

• Help -> About Firefox

• https://support.mozilla.org/kb/update-firefox-latest-version

This doesn't work. <Control> F never closes the search box on this release.

Also, as I said explicitly, Esc doesn't close the search bar. I could install an addon to make the search bar close or lose focus after some keyboard combination. However, as I also mentioned, I am attempting to write autohotkey scripts for my colleagues.

Since Firefox says that Esc closes the search bar, but Esc won't, I thought I'd ask why the feature is broken first, rather than going to other people's computers and getting permission from each of them to install an addon.

Please read my original post. Both responses suggested using Esc or Ctrl-F, which I mentioned isn't working.

BTW, thank you very much for suggesting hardware acceleration, Cor-el. Turning it off doesn't help. Firefox also has the same behavior in safe mode. (Sorry I didn't mention that, I tried it already.)

Did you try the Ctrl+F and ESC combination in case the find bar doesn't have focus?

No, that doesn't do anything. I've tried Ctrl, Shift, Esc, and F in every combination I could think of.

Are you seeing similar behavior?

Sorry.

It is two separate key sequences, first press Ctrl+F and release the Ctrl key and the F key and then press the ESC key.

Does ESC work otherwise to close or stop some action like loading a web page?

Holding Ctrl, then pressing and releasing F, and then pressing Esc, (and only releasing Ctrl after releasing Esc) will: A: Open the search bar if it is closed, B: Switch focus to the search bar if the search bar has been deselected, or C: Do nothing if the search bar is open and selected.

That is weird.

Try to do a clean reinstall to see if that has effect.

Download the Firefox installer and save the file to the desktop
*https://www.mozilla.org/en-US/firefox/all/ Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

• (32 bit Windows) "C:\Program Files\Mozilla Firefox\"
• (64 bit Windows) "C:\Program Files (x86)\Mozilla Firefox\"

Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you uninstall and reinstall or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

If you keep having problems then create a new profile to test if your current profile is causing the problem.

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Profile_backup

• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Clean_reinstall

Okay. Thank you! I'm going to have to wait until our system admin is in tomorrow to do that on this pc. However, I'll try this once I get home, since that Firefox browser exhibited the same issue when I was teleworking. (I updated that browser last Friday.)