ForecastFox | version 0.9.x and all satellite images versions? | Memory leak | Update or uninstall and install Forecastfox l10n. There are unconfirmed reports that there are also memory problems with versions 0.9.3 and 0.9.4. | [39][40]
[41] |
Prior to version 0.9.5.1 | Causes excessive CPU usage with Firefox 2.0 and Firefox 2.0.0.1 | Update to Firefox 2.0.0.2 and ForecastFox 0.9.5.1 | [42][43] |
Google Browser Sync | All? | Causes excessive CPU usage in general or with GIF animations | Uninstall | [44][45] |
? | May cause notably increased disk usage (in gigabytes) by creating large log files. May cause periodic Firefox freezes. | Uninstall | [46][47] |
Google Toolbar (official) | ? | "Send with GMail" option overrides default mail client. If theGoogle Toolbar is uninstalled, mail links may stop working in Firefox | If still installed, UNcheck "Send with GMail" in Google Toolbar Options. If uninstalled, go to about:config in Firefox, find the preference network.protocol-handler.external.mailto and reset to "true" (double-click will toggle). | [48] [49] |
1.0.* on windows 98, 2.0.20060404 beta and 2.0.20060515 beta | Causes Unresponsive Script Warning | The Google Toolbar is not compatible with Windows 95, 98, or ME. Fixed for supported OSs in latest version. | [50] |
2.0.20060404 beta and 2.0.20060515 beta | Leaks memory | Install the latest version from toolbar.google.com | [51] |
2.1.20060713 | Causes excessive disk activity | Disable Google Safe Browsing or install the latest version from toolbar.google.com | [52] |
3.x (beta?) | Windows error opening Internet shortcut or local HTML file - Firefox | Disable or uninstall | [53] [54] |
Google Web Accelerator | ? | Causes Firefox to crash on closing. | Uninstall Google Web Accelerator | [55] |
Greasemonkey | All | Greasemonkey scripts do not work on sites blocked by NoScript | Set NoScript to allow JavaScript on sites you wish to use Greasemonkey scripts on. | [56] |
Hebrew Calendar | Prior to 1.0.4.36 | Causes "ReferenceError: JEvent is not defined" | Update to a newer version | [57] |
IE Tab | All | Memory leak | Uninstall IE Tab and install IE View Lite | [58] |
iMacros | Prior to 0.5.0.4 | Causes excessive CPU usage | Update to a newer version | [59] |
ImgLikeOpera | 0.6.15 | "Refresh images in tab on tab select" option causes excessive CPU usage on tab change and erratic text box behaviour (i.e. losing caret after selection in google search text box). | Turn off "Refresh images in tab on tab select" option. | [60] |
Linky | 2.6 | Gray bar below the status bar with red arrow. | Uninstall Linky. | [61] |
McAfee SiteAdvisor | ? | "onLookupFailed 55 1" alerts. | Disable McAfee SiteAdvisor. | [62][63]
[64] |
22 | Firefox may fail to open after installing or updating theSiteAdvisor extension, which also may be installed as part of a McAfeesoftware suite. This SiteAdvisor support article describes the problem as a conflict between SiteAdvisor and automatic proxy configuration scripts in Firefox. | Either follow the workaround in the SiteAdvisor support article or end the firefox process that remains in memory, start Firefox in Safe Modeand uninstall via Tools -> Extensions. If SiteAdvisor is a McAfeesuite component it can also be removed using the McAfee uninstaller. | [65] [66] |
23 | Causes Firefox to crash with an error in Jar50.dll after installing or updating the SiteAdvisor extension or McAfee component. | Uninstall the SiteAdvisor extension or, if SiteAdvisor isinstalled as part of a McAfee software suite, remove the SiteAdvisorcomponent using the McAfee uninstaller. | [67] |
Media Player Connectivity | All? | Can cause Unresponsive Script Warning | Uninstall Media Player Connectivity | [68][69] |
Menu Editor | 1.2.4
(and 1.2.5?) | Middle mouse button no longer opens new links from web pages | Update to the latest version; if the issue persists, disable the extension | [70] [71] [72] |
Mouseless Browsing | All? | Can cause excessive CPU usage | Uninstall Mouseless Browsing | [73] |
Nightly Tester Tools | All | Allows incompatible extensions and themes to run; these incompatible add-ons can cause problems | Update your extensions and themes to those compatible with your version of Firefox | [74] |
NoScript | All | Causes an illegal operation in the Windows Media Playerplugin if it is blocking JavaScript on a page with embedded WindowsMedia | Do not block websites that have embedded Windows Media if you want to be able to play the media | [75] [76] |
FlashBlock requires JavaScript to work to block flash ads | Do not use both FlashBlock and NoScript together (NoScript includes Flash-blocking functionality) | [77] |
Greasemonkey scripts require JavaScript | Set NoScript to allow JavaScript on sites you wish to use Greasemonkey scripts on. | [78] |
All since 1.1.9.5 | Flashand other plugin content is blocked by default on untrusted sites, evencontent from trusted sites (e.g. YouTube.com) if embedded on anuntrusted site. | Uncheck the option to forbid Flash or other plugins inNoScript's Options\Plugins pane or temporarily allow the content byclicking on its placeholder. | [79] [80] [81] |
All since 1.1.0 | Java is blocked by default on untrusted sites | Uncheck "Forbid Java" in NoScript's Options\Plugins pane(Options\Advanced\Untrusted in earlier versions). In version 1.1.3 andlater you can temporarily allow Java content by clicking on itsplaceholder. | [82] [83] |
Prior to 1.1.3.9 | Causes Firefox to hog memory | Update to 1.1.3.9 or later | [84] |
"Numbered Links" | All | FormSpy (aka FireSpy) malware identifies itself as "Numbered Links". The real Numbered Links extension is harmless. See this forum topic for more information. | Uninstall the extension. Scan your system for viruses, particularly "FormSpy" and "Downloader-AXM". | [85][86] |
onFocusReload | ? | "Alert! Object Event" message. | Uninstall onFocusReload. | [87] |
RealPlayer Browser Record Plugin | 1.0 | This extension is included as an option when installing RealPlayer and can cause various issues including image display, form submission, and embedded Flash problems. | Uninstall or disable this extension in "Tools -> Add-ons -> Extensions". | [88] [89] [90] [91] |
ProCon | Prior to 1.5.2 | Replaces all words on webpages with asterisks (******) if set to "censure" words. Fixed in version 1.5.2. | Uninstall ProCon, restart Firefox, reset ProCon preferences in about:config, restart Firefox, reinstall. | [92] |
SearchStatus | All? | Causes Firefox to hang for short periods. | Uninstall SearchStatus | [93] |
SessionSaver | All | Leaks memory | Uninstall SessionSaver and install Session Manager | [94] |
Version 0.2 | Causes Unresponsive Script Warning when uploading files | Downgrade to version 0.2d | [95] |
Skype Extension for Firefox | All ? | Can cause web pages to continually refresh or stop loading and Firefox may hang or become unresponsive. Can also cause errors loading direct links to images or PDF files. | Disable or uninstall the extension. | [96] [97] [98] [99] |
Skype Web Toolbar | ? | Causes back, forward, reload and stop buttons or webpagecontent buttons to stop working; may also cause a blank address bar orunchanged URL when switching tabs or going to a new link. | Disable or uninstall the extension. Note: The Skype Web Toolbar is no longer supported as of 15-08-2007. | [100][101]
[102][103] |
SwitchProxy Tool | All | Causes new Firefox windows to freeze for a few seconds | Disable SwitchProxy's auto-update feature | [104] |
Tabbrowser Extensions (TBE) | All | General slowdown, conflicts with other extensions, can cause Firefox to not work at all | Uninstall TBE, use Tab Mix or Tab Mix Plus instead | [105] |
Tabbrowser Preferences (TBP) | All (for Firefox in some languages) | Gray bar below the status bar at the bottom of the screen which reads:<button id="catTabbedButton" label="&tabprefs.label;"
| Uninstall TBP | [106] |
1.2.8.4 | Bar at the bottom of the screen which reads:%tabprefsDTD;
| Uninstall TBP and install it directly from the author's website | [107] [108] |