Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

JavaScript doesn't seem to be working on localhost.

  • 8 replies
  • 12 have this problem
  • Last reply by janetmweiss

more options

I'm using Firefox 27 on Windows 7 and--all of a sudden, it seems--JavaScript has totally stopped working for websites on localhost. I've tried disabling my add-ons, restarting Firefox, clearing my cache, testing with the simplest script (basically just an alert() prompt that works fine in other browsers) but nothing. I load the page and nothing happens. Firebug (when I have it enabled) doesn't even detect any scripts in my localhost pages! The same pages work fine if they're hosted somewhere else, though. Help?

Chosen solution

Could you try a new profile?

Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

If the new profile works then you can transfer some files from an existing profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem.

If it still happens with a new and clean profile then the most likely cause is that you have security software that is blocking this JavaScript.

Read this answer in context 👍 1

All Replies (8)

more options

Sorry you are having this problem. I will try to help you with a solution. Please do not be afraid to ask if you have questions.

Try Firefox Safe Mode' to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that turns off some settings and disables most add-ons (extensions and themes).

(If you're using an added theme, switch to the Default theme.)

If Firefox is open, you can restart in Firefox Safe Mode from the Help menu by clicking on the Restart with Add-ons Disabled... menu item:

If Firefox is not running, you can start Firefox in Safe Mode as follows:

  • On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
  • On Mac: Hold the option key while starting Firefox.
  • On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
    (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)

Once you get the pop-up, just select "'Start in Safe Mode" Safe Mode Fx 15 - Win

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.

To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

If you are still having an issue try the following steps. This step will help you to give as much information as you can to our community to assist you in full.

In order to be able to find the correct solution to your problem, we require some more non-personal information from you. Please do the following:

  • Click the Firefox button at the top left, then click the Help menu and select Troubleshooting Information from the submenu. If you don't have a Firefox button, click the Help menu at the top and select Troubleshooting Information from the menu.

Now, a new tab containing your troubleshooting information should open.

  • At the top of the page, you should see a button that says "Copy text to clipboard". Click it.
  • Now, go back to your forum post and click inside the reply box. Press Ctrl+V to paste all the information you copied into the forum post.

If you need further information about the Troubleshooting information page, please read the article Use the Troubleshooting Information page to help fix Firefox issues.

One final step to try. Try reinstalling java. This is a step that can best be explained on the Java website. They offer a clean update and removal of old versions of Java.

Please keep in touch here and we should be able to bring you to a full solution. Thank you again.

more options

I already tried Safe Mode, which didn't help. I suppose I could try reinstalling Java, but my Java plugins are already disactivated so...? Anyway, I am pasting my troubleshooting information in two blocks, since it is too large to fit in one post.

Application Basics

Name: Firefox Version: 27.0.1 User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0

Crash Reports for the Last 3 Days

All Crash Reports


Name: Adblock Plus Version: 2.4.1 Enabled: false ID: {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}

Name: anonymoX Version: 2.1.1 Enabled: false ID:

Name: bug489729(Disable detach and tear off tab) Version: 2.1 Enabled: false ID: bug489729@alice0775

Name: BYTubeD - Bulk YouTube video Downloader Version: 1.1.1 Enabled: false ID:

Name: Config Descriptions Version: 1.0 Enabled: false ID: {1823e248-6bf4-f6f1-7901-65a68e8b6c1e}

Name: DownloadHelper Version: 4.9.21 Enabled: false ID: {b9db16a4-6edc-47ec-a1f4-b86292ed211d}

Name: DownThemAll! Version: 2.0.16 Enabled: false ID: {DDC359D1-844A-42a7-9AA1-88A850A938A8}

Name: Easy YouTube Video Downloader Version: 7.0 Enabled: false ID: {c0c9a2c7-2e5c-4447-bc53-97718bc91e1b}

Name: Firebug Version: 1.12.6 Enabled: false ID:

Name: FirePHP Version: 0.7.4 Enabled: false ID:

Name: Greasemonkey Version: 1.15 Enabled: false ID: {e4a8a97b-f2ed-450b-b12d-ee082ba24781}

Name: Hide Tab Bar With One Tab Version: 1.2beta3 Enabled: false ID: {e5bbc237-c99b-4ced-a061-0be27703295f}

Name: LeechBlock Version: 0.6.6 Enabled: false ID: {a95d8332-e4b4-6e7f-98ac-20b733364387}

Name: Long URL Please Mod Version: 0.5.1 Enabled: false ID: longurlplease@tseng

Name: ProxMate - Proxy on steroids! Version: 2.3.3 Enabled: false ID: jid1-QpHD8URtZWJC2A@jetpack

Name: Troubleshooter Version: 1.1a Enabled: false ID:

Name: Tumblr Savior Version: 0.4.11 Enabled: false ID: jid1-W5guVoyeUR0uBg@jetpack

Name: Web Developer Version: 1.2.5 Enabled: false ID: {c45c406e-ab73-11d8-be73-000a95be3b12}

more options

I lied. Three posts of trouble shooting information because I divided it up wrong. Ugh.

Important Modified Preferences

accessibility.typeaheadfind.flashBar: 0 browser.cache.disk.capacity: 358400 browser.cache.disk.smart_size.first_run: false browser.cache.disk.smart_size.use_old_max: false browser.cache.disk.smart_size_cached_value: 358400 browser.history_expire_days.mirror: 180 browser.places.importBookmarksHTML: false browser.places.smartBookmarksVersion: 4 true browser.sessionstore.max_windows_undo: 10 browser.sessionstore.upgradeBackup.latestBuildID: 20140212131424 browser.startup.homepage_override.buildID: 20140212131424 browser.startup.homepage_override.mstone: 27.0.1 browser.tabs.autoHide: true browser.tabs.drawInTitlebar: false browser.tabs.onTop: false dom.mozApps.used: true dom.w3c_touch_events.expose: false extensions.lastAppVersion: 27.0.1 font.internaluseonly.changed: true gfx.direct3d.last_used_feature_level_idx: 0 gfx.direct3d.prefer_10_1: true keyword.enabled: false network.cookie.cookieBehavior: 0 network.cookie.prefsMigrated: true network.http.spdy.enabled: false network.protocol-handler.warn-external.dnupdate: false places.database.lastMaintenance: 1392416836 places.history.expiration.transient_current_max_pages: 104858 places.history.expiration.transient_optimal_database_size: 163320298 places.last_vacuum: 1322238978 plugin.disable_full_page_plugin_for_types: application/vnd.adobe.xfdf,application/vnd.fdf,application/pdf plugin.importedState: true 0 plugin.state.npdeployjava: 0 print.print_printer: HP DeskJet 812C on COMPUTER print.printer_Adobe_PDF.print_bgcolor: false print.printer_Adobe_PDF.print_bgimages: false print.printer_Adobe_PDF.print_command: print.printer_Adobe_PDF.print_downloadfonts: false print.printer_Adobe_PDF.print_edge_bottom: 0 print.printer_Adobe_PDF.print_edge_left: 0 print.printer_Adobe_PDF.print_edge_right: 0 print.printer_Adobe_PDF.print_edge_top: 0 print.printer_Adobe_PDF.print_evenpages: true print.printer_Adobe_PDF.print_footercenter: print.printer_Adobe_PDF.print_footerleft: &PT print.printer_Adobe_PDF.print_footerright: &D print.printer_Adobe_PDF.print_headercenter: print.printer_Adobe_PDF.print_headerleft: &T print.printer_Adobe_PDF.print_headerright: &U print.printer_Adobe_PDF.print_in_color: true print.printer_Adobe_PDF.print_margin_bottom: 0.5 print.printer_Adobe_PDF.print_margin_left: 0.5 print.printer_Adobe_PDF.print_margin_right: 0.5 print.printer_Adobe_PDF.print_margin_top: 0.5 print.printer_Adobe_PDF.print_oddpages: true print.printer_Adobe_PDF.print_orientation: 0 print.printer_Adobe_PDF.print_pagedelay: 500 print.printer_Adobe_PDF.print_paper_data: 1 print.printer_Adobe_PDF.print_paper_height: 11.00 print.printer_Adobe_PDF.print_paper_size_type: 0 print.printer_Adobe_PDF.print_paper_size_unit: 0 print.printer_Adobe_PDF.print_paper_width: 8.50 print.printer_Adobe_PDF.print_reversed: false print.printer_Adobe_PDF.print_scaling: 1.00 print.printer_Adobe_PDF.print_shrink_to_fit: true print.printer_Adobe_PDF.print_to_file: false print.printer_Adobe_PDF.print_unwriteable_margin_bottom: 0 print.printer_Adobe_PDF.print_unwriteable_margin_left: 0 print.printer_Adobe_PDF.print_unwriteable_margin_right: 0 print.printer_Adobe_PDF.print_unwriteable_margin_top: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_bgcolor: false print.printer_HP_DeskJet_812C_on_COMPUTER.print_bgimages: false print.printer_HP_DeskJet_812C_on_COMPUTER.print_command: print.printer_HP_DeskJet_812C_on_COMPUTER.print_downloadfonts: false print.printer_HP_DeskJet_812C_on_COMPUTER.print_edge_bottom: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_edge_left: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_edge_right: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_edge_top: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_evenpages: true print.printer_HP_DeskJet_812C_on_COMPUTER.print_footercenter: print.printer_HP_DeskJet_812C_on_COMPUTER.print_footerleft: &PT print.printer_HP_DeskJet_812C_on_COMPUTER.print_footerright: &D print.printer_HP_DeskJet_812C_on_COMPUTER.print_headercenter: print.printer_HP_DeskJet_812C_on_COMPUTER.print_headerleft: &T print.printer_HP_DeskJet_812C_on_COMPUTER.print_headerright: &U print.printer_HP_DeskJet_812C_on_COMPUTER.print_in_color: true print.printer_HP_DeskJet_812C_on_COMPUTER.print_margin_bottom: 0.5 print.printer_HP_DeskJet_812C_on_COMPUTER.print_margin_left: 0.5 print.printer_HP_DeskJet_812C_on_COMPUTER.print_margin_right: 0.5 print.printer_HP_DeskJet_812C_on_COMPUTER.print_margin_top: 0.5 print.printer_HP_DeskJet_812C_on_COMPUTER.print_oddpages: true print.printer_HP_DeskJet_812C_on_COMPUTER.print_orientation: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_pagedelay: 500 print.printer_HP_DeskJet_812C_on_COMPUTER.print_paper_data: 1 print.printer_HP_DeskJet_812C_on_COMPUTER.print_paper_height: 11.00 print.printer_HP_DeskJet_812C_on_COMPUTER.print_paper_size_type: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_paper_size_unit: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_paper_width: 8.50 print.printer_HP_DeskJet_812C_on_COMPUTER.print_reversed: false print.printer_HP_DeskJet_812C_on_COMPUTER.print_scaling: 1.00 print.printer_HP_DeskJet_812C_on_COMPUTER.print_shrink_to_fit: true print.printer_HP_DeskJet_812C_on_COMPUTER.print_to_file: false print.printer_HP_DeskJet_812C_on_COMPUTER.print_unwriteable_margin_bottom: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_unwriteable_margin_left: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_unwriteable_margin_right: 0 print.printer_HP_DeskJet_812C_on_COMPUTER.print_unwriteable_margin_top: 0 print.printer_HP_Officejet_4620_series_(Network).print_bgcolor: false print.printer_HP_Officejet_4620_series_(Network).print_bgimages: false print.printer_HP_Officejet_4620_series_(Network).print_colorspace: print.printer_HP_Officejet_4620_series_(Network).print_command: print.printer_HP_Officejet_4620_series_(Network).print_downloadfonts: false print.printer_HP_Officejet_4620_series_(Network).print_duplex: 1769629472 print.printer_HP_Officejet_4620_series_(Network).print_edge_bottom: 0 print.printer_HP_Officejet_4620_series_(Network).print_edge_left: 0 print.printer_HP_Officejet_4620_series_(Network).print_edge_right: 0 print.printer_HP_Officejet_4620_series_(Network).print_edge_top: 0 print.printer_HP_Officejet_4620_series_(Network).print_evenpages: true print.printer_HP_Officejet_4620_series_(Network).print_footercenter: print.printer_HP_Officejet_4620_series_(Network).print_footerleft: &PT print.printer_HP_Officejet_4620_series_(Network).print_footerright: &D print.printer_HP_Officejet_4620_series_(Network).print_headercenter: print.printer_HP_Officejet_4620_series_(Network).print_headerleft: &T print.printer_HP_Officejet_4620_series_(Network).print_headerright: &U print.printer_HP_Officejet_4620_series_(Network).print_in_color: true print.printer_HP_Officejet_4620_series_(Network).print_margin_bottom: 0.5 print.printer_HP_Officejet_4620_series_(Network).print_margin_left: 0.5 print.printer_HP_Officejet_4620_series_(Network).print_margin_right: 0.5 print.printer_HP_Officejet_4620_series_(Network).print_margin_top: 0.5 print.printer_HP_Officejet_4620_series_(Network).print_oddpages: true print.printer_HP_Officejet_4620_series_(Network).print_orientation: 0 print.printer_HP_Officejet_4620_series_(Network).print_page_delay: 50 print.printer_HP_Officejet_4620_series_(Network).print_paper_data: 1 print.printer_HP_Officejet_4620_series_(Network).print_paper_height: 11.00 print.printer_HP_Officejet_4620_series_(Network).print_paper_name: print.printer_HP_Officejet_4620_series_(Network).print_paper_size_type: 0 print.printer_HP_Officejet_4620_series_(Network).print_paper_size_unit: 0 print.printer_HP_Officejet_4620_series_(Network).print_paper_width: 8.50 print.printer_HP_Officejet_4620_series_(Network).print_plex_name: print.printer_HP_Officejet_4620_series_(Network).print_resolution: 979857001 print.printer_HP_Officejet_4620_series_(Network).print_resolution_name: print.printer_HP_Officejet_4620_series_(Network).print_reversed: false print.printer_HP_Officejet_4620_series_(Network).print_scaling: 1.00 print.printer_HP_Officejet_4620_series_(Network).print_shrink_to_fit: true print.printer_HP_Officejet_4620_series_(Network).print_to_file: false print.printer_HP_Officejet_4620_series_(Network).print_unwriteable_margin_bottom: 0 print.printer_HP_Officejet_4620_series_(Network).print_unwriteable_margin_left: 0 print.printer_HP_Officejet_4620_series_(Network).print_unwriteable_margin_right: 0 print.printer_HP_Officejet_4620_series_(Network).print_unwriteable_margin_top: 0 privacy.clearOnShutdown.cookies: false privacy.donottrackheader.enabled: true privacy.sanitize.migrateFx3Prefs: true privacy.sanitize.timeSpan: 3 security.warn_submit_insecure: false security.warn_submit_insecure.show_once: false security.warn_viewing_mixed: false security.warn_viewing_mixed.show_once: false storage.vacuum.last.index: 1 storage.vacuum.last.places.sqlite: 1391536163

user.js Preferences

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

more options


Adapter Description: Intel(R) HD Graphics 4000 Adapter Description (GPU #2): NVIDIA GeForce GT 630M Adapter Drivers: igdumd64 igd10umd64 igd10umd64 igdumd32 igd10umd32 igd10umd32 Adapter Drivers (GPU #2): nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um Adapter RAM: Unknown Adapter RAM (GPU #2): 2047 Device ID: 0x0166 Device ID (GPU #2): 0x0de9 DirectWrite Enabled: false (6.2.9200.16571) Driver Date: 12-12-2012 Driver Date (GPU #2): 5-12-2013 Driver Version: Driver Version (GPU #2): GPU #2 Active: false GPU Accelerated Windows: 0/1 Basic Vendor ID: 0x8086 Vendor ID (GPU #2): 0x10de WebGL Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics 4000 Direct3D9Ex vs_3_0 ps_3_0) windowLayerManagerRemote: false AzureCanvasBackend: skia AzureContentBackend: cairo AzureFallbackCanvasBackend: cairo AzureSkiaAccelerated: 0


Incremental GC: true


Activated: false Prevent Accessibility: 0

Library Versions

NSPR Expected minimum version: 4.10.2 Version in use: 4.10.2

NSS Expected minimum version: 3.15.4 Basic ECC Version in use: 3.15.4 Basic ECC

NSSSMIME Expected minimum version: 3.15.4 Basic ECC Version in use: 3.15.4 Basic ECC

NSSSSL Expected minimum version: 3.15.4 Basic ECC Version in use: 3.15.4 Basic ECC

NSSUTIL Expected minimum version: 3.15.4 Version in use: 3.15.4

more options

Chosen Solution

Could you try a new profile?

Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

If the new profile works then you can transfer some files from an existing profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem.

If it still happens with a new and clean profile then the most likely cause is that you have security software that is blocking this JavaScript.

more options

Thank you for that information. Here are a few more potential solutions. I wont give up if these dont work, so please let me know if they do not.

Many site issues can be caused by corrupt cookies or cache. In order to try to fix these problems, the first step is to clear both cookies and the cache. Note: This will temporarily log you out of all sites you're logged in to. To clear cache and cookies do the following:

  1. Go to Firefox > History > Clear recent history or (if no Firefox button is shown) go to Tools > Clear recent history.
  2. Under "Time range to clear", select "Everything".
  3. Now, click the arrow next to Details to toggle the Details list active.
  4. From the details list, check Cache and Cookies and uncheck everything else.
  5. Now click the Clear now button.

Further information can be found in the Clear your cache, history and other personal information in Firefox article.

Please, be sure on this next step that you are sure you wish to do this. You may want to jot down your ad ons, and bookmarks or elect to keep them by prompt.

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 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!

Please report back to see if this helped you!

Thank you.

Modified by jasonstover9

more options

This did the trick, cor-el. Thank you.

more options

As I mentioned in my original post, I'd already cleared my cache. At any rate, cor-el's response worked, so I think I'm good for now.