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• Check plugins
• Fix problems with Facebook games, chat and more
• Warning Unresponsive script
• Firefox hangs or is not responding

In the last case try a clean reinstall:

Certain Firefox problems can be solved by performing a Clean reinstall. This means you remove Firefox program files and then reinstall Firefox. Please follow these steps:

Note: You might want to print these steps or view them in another browser.

1. Download the latest Desktop version of Firefox from http://www.mozilla.org and save the setup file to your computer.
2. After the download finishes, close all Firefox windows (click Exit from the Firefox or File menu).
3. Delete the Firefox installation folder, which is located in one of these locations, by default:
   • Windows:
     • C:\Program Files\Mozilla Firefox
     • C:\Program Files (x86)\Mozilla Firefox
   • Mac: Delete Firefox from the Applications folder.
   • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
4. Now, go ahead and reinstall Firefox:
   1. Double-click the downloaded installation file and go through the steps of the installation wizard.
   2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

More information about reinstalling Firefox can be found here.

WARNING: Do not run Firefox's uninstaller or use a third party remover as part of this process, because that could permanently delete your Firefox data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be recovered unless they have been backed up to an external device!

Also:

• Create a screenshot of the problem

No sooner that I post this, that Facebook automatically updates my browser in my most recent session - and I'm not even sure what the update was. Now, it's almost completely unusuable. It's as if each update makes it worse. Seriously, this isn't even script errors, this time. It's literally hanging for minutes on end.

What the heck was the update? How do I find that out so that I can remove it? This is an utter mess.

BTW, back on the script error, this is the script I'm getting whenever I access a Facebook page:

Script: https://fbstatic-a.akamaihd.net/rsrc.php/v2/yK/r/17CARsPX6zq.js:30

All i see is:

/*bcs*/

FB has a ton of Flash content. I personally do not use FB, however I am aware it uses Flash extensively.

Are you referring to crashes related to flash ?

Can you get a crash report perhaps?

EDIT: IF you feel this is Flash related i do have a unique and creative solution that i came up with myself and have resolved my Firefox/flash crashes successfully and been crash free for almost a year. Flash related only though.

I think you misunderstood. I'm getting hangs and then script errors, not full browsers crashes. Flash has its own problems, but those I've been able to deal with or at least tolerate, as they happen more rarely (mostly because I rarely have my flash plug-in activated as it slows down my computer).

Your profile folder contains a user.js file, which includes preferences that were not created by Firefox.

so you may want to also check for a user.js file and DELETE that.

• https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save#w_user-js-file-overriding-preferences

You can check for problems with current Shockwave Flash plugin versions and try these:

• disable protected mode in the Flash plugin (Flash 11.3+ on Windows Vista and later)
• disable hardware acceleration in the Flash plugin

See also:

• http://kb.mozillazine.org/Flash#Troubleshooting

I said above that the Flash player problem is one I've come to tolerate. This is not what this current support question is about. The problem I wrote about in my original post is a specific scripting error. Arman Routh supplied me with a possible answer that I will try and test.

Arman,

I've seen this before. I believe I tried it to no avail, but I'll try again. Is this something I'm going to have to do EVERY session of Firefox? If so, this is not really a fix, is it? Rather, like all of the "fixes" this seems to be a temporary work-around.

Arman, instead of deleting the file, I actually tried the directions in the link you provided, and couldn't even get the file to open. BTW, even if I were to open it, what line would I change in the notebook? They give no directions.

Also, even if I were to delete this file, isn't it recreated every session?

Hello FireFoxFan1,

User.js file are either created by the users or by some other third party application which modify the preferences of Firefox automatically, if you have gone through the Link i have provided earlier you may get to know some of those third party applications and how they overrides your settings.

You can go ahead and delete the .js file and if it reappears again then surely one of the third party application or some malware is causing the problem.

please reply back after deleting the file. Thank you.

I will go delete it, now. Out of curiosity, though, what third-party app may be creating this file? I ask, because I believe I've deleted it in the past and it is created every new session. I've posted all of my browser information in the original post; that should help you.

This file recreates itself. What third-party app could be recreating this file? I really need help.

Hi FireFoxFan1,
Sorry you continue to have problems.

If you have malware installed and it is not removed problems may be expected to re-occur.

Run scans with multiple and up-to-date tools. Hopefully it will be detected and removed. I would not suggest you try any manual hacks or edits of the Windows registry. (Once rogue files are removed any residual registry entry will not normally do any harm.)

Also please paste the content of the recreated js file in to your reply that may give someone a clue. (Edit it if it contains confidential info, but say what sort of confidential info it does contain) - - - - - Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• TDSSKiller - AntiRootkit Utility
• Hitman Pro
• ESET Online Scanner
• AdwCleaner: (for adware)
• Kaspersky Free security scan

You need to use multiple and up-to-date tools as they will not all pick up the same things.

Microsoft Security Essentials is a good FREE permanent antivirus for Windows 7/Vista/XP if you don't already have one.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

I think I have nothing to add to our earlier discussion where you said a new profile ran better: Habitual Javascript Errors in Firefox 26.0.

The other thread contains more information. This thread appears to me to be an unnecessary duplication. Closing this thread as a triplicate.

Please continue with open thread

• Habitual Javascript Errors in Firefox 26.0
  /questions/982984?page=2#answer-527488
• also note similar prior thread
  Why do I keep getting this unresponsive script error?
  /questions/965047