This article describes what to do if Firefox doesn't open when you click the Firefox icon.
- If you get a message you can dismiss (e.g. "TypeError: Components.classes["@ ... ;1"] is undefined", "onload error TypeError: ...", "Exc in ev handl: ...") and can open Firefox, see .
- If Firefox starts but won't load any websites, Websites don't load see - troubleshoot and fix error messages .
Firefox is already running but is not responding
Your Firefox profile cannot be loaded. It may be missing or inaccessible
Failed to read the configuration file
This error is caused by a problem with Firefox program files. The solution is to remove the Firefox program and then reinstall Firefox. (This will not remove your passwords, bookmarks or other user data and settings which are stored in a separate folder.)
- Delete the Firefox installation directory, found in one of these locations by default:
- C:\Program Files\Mozilla Firefox
- C:\Program Files (x86)\Mozilla Firefox
- Use another browser to download the Firefox installer from the Firefox download page and install it. See How to download and install Firefox on Windows for details.
XULRunner - Error
If you see the message "XULRunner - Error: Platform version
There was an error launching the application
This error indicates that either Firefox is not installed or your shortcut to it is incorrect. Make sure that Firefox is installed at the location specified by the shortcut. If it isn't, install Firefox if necessary, then modify the shortcut to point to the correct location.
Error opening file for writing…
If you receive the above error when launching Firefox on a Windows system, you may be required by Firefox to log in as an administrator. You can either reboot the computer or, if you have an administrator account, you can execute the program as an administrator.
- Find the firefox.exe program file in the Firefox application folder on your system.
- Right-click the icon.
- Select Run As… .Select Run As Administrator… . Select The following user:. From the User name drop-down, select Administrator or another user that has administrator privileges. Enter the password required to log in to this account. Click OK .
- The Firefox application is started using the administrator Windows account. The user that was used to log in to Windows at startup is still the active one.
Other error messages
If you get another error message (e.g. "XML Parsing Error: undefined entity Location", "Secure Connection Failed … uses an invalid security certificate"), see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems .
No error message
If you click the Firefox icon but no Firefox window opens and no error message is shown, a simple first step is to restart your computer and then try again. If Firefox still does not start, see the following sections.
Firefox will not start after updating
- If you use certain versions of ZoneAlarm or other Internet security software that includes a "Virtual Browsing" feature, it can prevent Firefox from starting. Check virtualization settings and clear the virtual cache, if your Internet security software includes this feature, or visit the software provider's support site for more help.
Firefox will not start after installing add-ons
If Firefox previously worked but stopped after you installed extensions or themes, see
Many users, including myself, have encountered such a frequent fox browser problem as bookmarks not opening. It consists in the fact that when you click on the “+” button, a new bookmark does not open. Restarting the browser, as a rule, does not give any results, however, there is still a way out of the situation when bookmarks in Mozilla do not open.
There are several troubleshooting scenarios - quick, and long. And now, in order, I will tell about them.
Quick option
The most effective solution, which is usually used to restore a working state of FireFox, is to roll it back to its original state. This function is a built-in feature of the browser, and it is performed in just a few clicks.
- All installed add-ons will be disabled.
- The user profile will be re-created, and all settings from the previous profile will be transferred to a special folder, so that in fact you will not lose any saved sites in your favorites, or any other information.
But any changes made to the browser itself (which are probably why bookmarks do not open in Mozilla Firefox) will be canceled.
So, in order to return the browser to its original state, you will need:
- Run it.
- Open the main menu by pressing the button on the right side of the toolbar.
- Click on the question mark icon.
- Select "Troubleshooting Information".
On the page that opens, you just need to click on the "Clear FireFox" button and confirm the action to be performed. The browser will close and reopen after a while in its standard state - as if it had just been reinstalled.
Important! After the cleanup is done, check the contents of your desktop. A folder should appear on it where all information from the previous profile will be stored - it will not be good if, due to the fact that your bookmarks do not open in Mozilla Firefox, important data and saved links will be lost.
long option
To fix your problem in the second way, you do not need to return the browser to the default settings. Here you will need to arm yourself with patience, and do the same procedure several times.
Judging by the experience of Firefox users, the problem may be caused by some installed extension (you can read more about removing plugins). Therefore, if your bookmarks do not open in Mozilla, you will need:
- Launch browser.
- Open the main menu of the browser and go to the "add-ons" section.
- Open the "Extensions" tab and start turning off each of the applications you have installed one by one, restarting the browser and checking the functionality of opening bookmarks.
Advice! First of all, pay attention to extensions that make changes to the browser toolbar. All kinds and other publishers should be checked first.
After the procedures done (it doesn't matter which of the two described paths you decide to go), the function of opening a new page should work fine. I hope this article was useful for you, and in the future you will keep track of which extensions are installed in your browser!
A fairly common situation: you double-clicked on the Mozilla Firefox shortcut on the desktop or opened this application from the taskbar, but faced with the fact that the browser refuses to start.
Unfortunately, the problem when the Mozilla Firefox browser refuses to start is quite common, and various reasons can affect its appearance. Today we will look at the main causes, as well as ways to fix Mozilla Firefox launch problems.
Option 1: "Firefox is running and not responding"
One of the more common Firefox crash situations is when you try to launch the browser but instead get a message "Firefox is running and not responding" .
As a rule, a similar problem appears after the previous incorrect closing of the browser, when it continues to execute its processes, thus preventing a new session from starting.
First of all, we need to end all Firefox processes. To do this, press the keyboard shortcut Ctrl+Shift+Esc , to open "Task Manager" .
In the window that opens, you need to go to the tab "Processes" . Locate the "Firefox" process ("firefox.exe"), right-click on it, and from the context menu that appears, select "Remove task" .
If you find other processes related to Firefox, they will also need to be terminated.
After completing these steps, try launching the browser.
If Mozilla Firefox still won't start, still giving the "Firefox is running and not responding" error, then in some cases this may indicate that you do not have the necessary access rights.
To check this, you will need to get into the profile folder. Of course, it is easier to do this using Firefox itself, but given that the browser does not start, we will use another method.
Press the simultaneous key combination on the keyboard Win+R. The Run window will appear on the screen, in which you will need to enter the following command and press the Enter key:
%APPDATA%\Mozilla\Firefox\Profiles\
The profile folder will be displayed on the screen. As a rule, if you did not create additional profiles, you will see only one folder in the window. If you are using multiple profiles, you will need to complete the following steps individually for each profile.
Right-click on the Firefox profile and in the context menu that appears, go to "Properties" .
A window will appear on the screen in which you need to go to the tab "General" . At the bottom of the window, make sure you have the checkbox checked "Only for reading" . If there is no checkmark (dot) next to this item, you must set it yourself, and then save the settings.
Option 2: "Error reading configuration file"
If the screen displays a message after trying to launch Firefox "Error reading configuration file" , then this means that there are problems with the Firefox files, and the easiest way to solve the problem is to reinstall Mozilla Firefox.
First of all, you will need to completely remove Firefox from your computer. We have already discussed how this task can be accomplished in one of our articles.
Open Windows Explorer and delete the following folders:
C:\Program Files\Mozilla Firefox
C:\Program Files (x86)\Mozilla Firefox
And only after you complete the removal of Firefox, you can start downloading the new version from the official website of the developer.
Option 3: "Error opening file for writing"
An error of this kind is displayed, as a rule, in cases where you use an account on a computer without administrator rights.
Accordingly, in order to solve the problem, you need to get administrator rights, but this can be done specifically for the application being launched.
Simply right-click on the Firefox shortcut on your desktop, and from the context menu that appears, click on "Run as administrator" .
A window will appear on the screen in which you will need to select an account that has administrator rights, and then enter a password from it.
Option 4: "Your Firefox profile cannot be loaded. It may be damaged or unavailable"
Such an error clearly hints to us that there are problems with the profile, for example, it is not available or is completely absent on the computer.
As a rule, a similar problem occurs if you have renamed, moved, or completely deleted the Firefox profile folder.
Based on this, you have several ways to solve the problem:
1. Move the profile to its original location if you have moved it before;
2. If you renamed the profile, then it must be given the previous name;
3. If you cannot use the first two methods, then you will need to create a new profile. Keep in mind that by creating a new profile, you will get pure Firefox.
In order to start creating a new profile, open the "Run" window with the keyboard shortcut Win+R . In this window, you will need to run the following command:
firefox.exe -P
The Firefox profile management window will appear on the screen. We need to resort to creating a new profile, so click on the button "Create" .
Enter a name for the profile, and, if necessary, in the same window specify the location on the computer where the profile folder will be stored. Finish creating your profile.
The Firefox profile management window will reappear on the screen, in which you will need to highlight the new profile, and then click on the button "Launching Firefox" .
Option 5: Firefox crash error
A similar problem manifests itself when you launch the browser. You may even have its window appear, but the application closes abruptly, and a message about the fall of Firefox is displayed on the screen.
In this case, various factors can cause Firefox to crash: viruses, installed add-ons, themes, etc.
First of all, in this case, you will need to scan with your antivirus or a special healing utility, for example, Dr.Web CureIt.
After performing the scan, be sure to restart your computer, and then check that the browser is working.
If the problem persists, then you should try to perform a complete reinstallation of the browser, after completely removing the web browser from the computer.
After the removal is complete, you can proceed to install the latest version of the browser from the official website of the developer.
Option 6: "XULRunner Error"
If you get the XULRunner Error error on your screen when you try to launch Firefox, it may indicate that you have an outdated version of Firefox installed on your computer.
You will need to completely remove Firefox from your computer, which we have already discussed on our website before.
After completing the complete removal of the browser from the computer, download the new version of the web browser from the official website of the developer.
Option 7: Mozilla does not open, but it does not give an error
1) If the browser was working normally before, but at some point it stopped starting, the most effective way to fix the problem is to perform a system restore.
This procedure will allow you to restore the system to the moment when the browser was working correctly. The only thing that this procedure will leave is user files (documents, music, photos and videos).
To start the system rollback process, open the menu "Control Panel" , set the view mode in the upper right corner "Small Signs" and then open the section "Recovery" .
In the window that opens, select the item "Starting System Restore" and wait a few moments.
Pick an appropriate rollback point when Firefox was working fine. Please note that depending on the changes made since then, the system restore can take from several minutes to several hours.
2) Some antivirus products can cause problems with Firefox. Try to pause them and check if Firefox is working.
If, according to the results of the check, an antivirus or other security program was the cause, it will need to disable the network scanning function or another function related to the browser or access to the network.
3) Try starting Firefox in safe mode. To do this, hold down the Shift key and click on the browser shortcut.
If the browser starts up normally, then this indicates a conflict between the browser and installed extensions, themes, etc.
First, disable all browser add-ons. To do this, click on the menu button in the upper right corner, and then in the window that appears, go to the section "Additions" .
In the left pane, go to the tab "Extensions" , and then disable all extensions. It would be useful if you completely remove them from the browser.
If you have third-party Firefox themes installed, try reverting to the default theme. To do this, go to the tab "Appearance" and make a theme "Standard" theme by default.
And finally, try disabling hardware acceleration. To do this, open the browser menu and go to the section "Settings" .
On the left side of the window, go to the tab "Additional" , and then open the subtab "General" . Here you will need to uncheck the box. "Use hardware acceleration whenever possible" .
After completing all the steps, open the browser menu and click on the icon in the lower area of \u200b\u200bthe window "Exit" . Try starting your browser in normal mode.
4) Reinstall your browser and create a new profile. How to accomplish this task has already been described above.
And a small conclusion. Today we looked at the main ways to fix problems with the launch of the Mozilla Firefox browser. If you have your own method of fixing the problem, share it in the comments.
This article describes what to do if the Firefox window does not appear after you click the Firefox icon.
- If you receive a message that you can ignore (for example, "TypeError: Components.classes["@ ... ;1"] is undefined", "onload error TypeError: ...", "Exc in ev handl: ...") and launch Firefox, see Troubleshoot extensions, themes, and hardware acceleration issues for common Firefox issues.
- If Firefox starts but won't load any websites, see Websites won't load - troubleshooting and fixing errors.
Error reading configuration file
This error occurs due to issues with the Firefox program files. The solution is to uninstall Firefox and then reinstall it. (This action will not delete your passwords, bookmarks, or other user data and settings that are stored in a separate profile folder.)
- Delete the Firefox installation directory, located by default in one of these locations:
- C:\Program Files\Mozilla Firefox
- C:\Program Files (x86)\Mozilla Firefox
- Use a different browser to download the Firefox installation file from the Firefox download page and install it. For more information, read the article How to download and install Firefox on Windows.
XULRunner error
If you see a message "Error - XULRunner: Platform Version
An error occurred while starting the application
This error means that either Firefox is not installed or your shortcut to it is incorrect. Make sure Firefox is installed in the location indicated on the shortcut. If it doesn't, install Firefox if necessary, and then change the shortcut to point to the correct location.
Error opening file for writing...
If you get this error when starting Firefox on Windows, then you may need to log in as an administrator. You can restart your computer or, if you have an administrator account, then you can run the program as an administrator.
- Locate the firefox.exe program file in the Firefox application folder on your computer.
- Right click on its icon.
- Select Run as.... Select Running as administrator.... Select The account of the specified user:. From the username dropdown menu, select Administrator or another user with administrator rights. Enter the password required to log into this account. Press the OK button.
- The Firefox application is launched using a Windows Administrator account. The user that was used to sign in to Windows at startup will still be active.
Other error messages
No error messages
If you click the Firefox icon but no Firefox window opens and no error messages appear, the first step is to restart your computer and try again. If Firefox won't start, see the following sections.
Firefox won't start after update
- If you are using certain versions of ZoneAlarm or other internet security software that include the Virtual Browsing feature, this may prevent Firefox from opening. Check your virtualization settings and clear the virtual cache if your internet security software includes this feature, or visit the software vendor's support site for more help.
Firefox won't start after installing add-ons
If Firefox used to work but stopped working after you installed extensions or themes, see
After a long period of operation or immediately after downloading from the network, the mozilla firefox program refuses to turn on at a normal working pace, does not start at all. There can be many reasons for such a reaction, and in order to efficiently eliminate malfunctions, it is worth taking a closer look at their true nature.
Browser not working
Mozilla's fast and feature rich system element is installed on many mobile and desktop devices. Reviews about his work are almost always positive, but often netizens complain about launch problems.
Almost always the system does not open after a long service or Yandex refuses to boot, and each problematic situation of this type has its own explanation. The most common malfunctions that cause such a problematic situation should be reviewed now.
Reasons for not responding to the program
When asked why the Mozil program does not work, people cannot give an unambiguous answer, because not everyone is well acquainted with modern technological features and processes. There are several possible scenarios for the development of situations in which Yandex or Mozilla Firefox cannot start on the device in use. The most common characteristics of this level should be called:
- lack of timely update of the extension;
- the presence of viruses inside the used gadget;
- randomly generated process of forced closing of the content component;
- system failures, both in terms of software operation and within a technical device;
- the installed version of Firefox is not compatible with a specific PC or mobile-type gadget.
The system refuses to open at all or, in some cases, starts up, and then immediately closes when you enter Yandex or another site. Often malfunctions and failures occur precisely after restarting the multimedia device, prolonged network work, opening several browsers together, programs that prevent the normal functional activity of other extensions.
Possible ways to solve the problem
If the opening system element hangs so much that it is completely impossible to cooperate productively with it, you should not try to bring it to life, but rather look for productive methods to solve such a serious problem.
In order to open and use the specified system software as quickly as possible, with high quality, it is worth trying to perform the following resuscitation actions:
One of these tips should help you open the system, go to the Yandex search engine and use Mozilla effectively.
