Firefox Extension Download Failed
Download failed. Please check your connection. – Mozilla …
Hi whatthe, there are some glitches with the addition of the new certificate in Firefox 66. 0. 4.
First, can you check whether it got installed? We’ll look on the Options page:
Windows: “3-bar” menu button (or Tools menu) > Options
Mac: “3-bar” menu button (or Firefox menu) > Preferences
Linux: “3-bar” menu button (or Edit menu) > Preferences
Any system: type or paste about:preferences into the address bar and press Enter/Return to load it
In the search box at the top of the page, type cert and Firefox should filter to the Certificates section. Click the “View Certificates” button.
In the Certificate Manager dialog, click the “Authorities” tab. This is listed in alphabetical order by “issuer. ” Scroll down to where “Mozilla Corporation” should be. Is it there? I am attaching a screenshot for comparison.
If the certificate did not install:
Do you use a Master Password?
For some reason, having a master password set in Firefox 55 or earlier can cause a problem. You can change the password and re-save it as a workaround. Then clear the flag indicating to Firefox that you already got the update so it tries again. Here are the details:
(1) Change your Master Password
You can change the Master Password from itself to the same thing again. See the last section of this article entitled “Changing the master password”: Use a Primary Password to protect stored logins and passwords
(2) Reset a preference
This preference is set when the new certificate is inserted, and prevents it from being done again. We need to check whether it was added and, if it was, switch it off.
(A) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.
(B) In the search box above the list, type or paste signer and pause while the list is filtered
(C) If the preference is bolded and “modified” to true, double-click it to set it to false
If you do not have that preference, great, no need to create it.
(3) Exit and restart Firefox and see whether it adds the certificate this time
Any luck?
Unable to install add-ons (extensions or themes) | Firefox Help
An inability to install an extension can be the result of problems with the extension, Firefox preferences, or the version of Firefox you are using. This article describes various causes of install problems and what you can do to address them.
Table of Contents1 Add-on is not compatible2 Firefox has prevented this site from installing an unverified add-on3 Add-on has a high risk of causing stability or security problems and can’t be installed4 Firefox prevented the site from asking you to install software5 You are asked to download the add-on, rather than installing it6 Nothing happens when you click the install link7 Corrupt extension files8 Conflict with other extensions
An internal file in each add-on indicates the range of Firefox versions with which the extension is compatible. In the Firefox Add-ons area of Mozilla, you can review version compatibility information on the page for each available extension.
If your installed version of Firefox does not fit within that range, installing the add-on results in an error, indicating that the add-on is not compatible. If your version of Firefox is incompatible with the add-on, you can:
Update to the latest version of Firefox. For more information, see Update Firefox to the latest release.
Find a version of the add-on that is compatible with your version of Firefox. The Firefox Add-ons website usually has the most up to date version of each add-on.
Use a different extension. For many extensions, there are similar extensions that provide the same functionality. For more information, see Firefox Add-ons.
Contact the author of the add-on at the support site listed on its add-on page. (Note: posting a review is not effective and will not reach the author. )
Firefox protects you against malware and browser hijackers by blocking third-party add-ons that are not digitally signed and verified by Mozilla. For more information, see Add-on signing in Firefox.
Certain add-ons have been blocklisted by Mozilla for being unsafe. For more information, see Add-ons that cause stability or security issues are put on a blocklist.
By default, Firefox permits you to install add-ons only from trusted websites. If the website from which you are installing add-on is not on the trusted websites list, a yellow bar appears across the top of the web page with a message similar to the following:
Firefox prevented this site () from asking you to install software on your computer.
To allow the site, click Allow in the yellow bar.
To add the site to the trusted sites list:
In the Menu bar at the top of the screen, click and select.
Click the menu button and select the menu button and select.
Select the panel and go down to the Permissions section.
At the right of Warn you when sites try to install add-ons, click Exceptions….
In the Allowed Websites – Add-ons Installation dialog, the list of permitted sites is displayed. The current site URL is inserted into the text field.
To allow the site, click Allow. Then, click Save Changes.
Close the about:preferences page. Any changes you’ve made will automatically be saved.
Some websites serve add-ons as downloads, requiring you to download the file to your computer, before installing it.
These files are usually or files.
Download the file to your local computer.
Click the menu button, click and select.
To add the downloaded add-on to the list of available add-ons, drag and drop the file into the Add-ons window. The add-on is added to the list.
The installation process should begin.
If you click an install link and nothing happens, you should verify that JavaScript is enabled. For more information, see JavaScript settings and preferences for interactive web pages.
Corrupt extension configuration files can cause problems when trying to install an extension. Deleting these files will make Firefox recreate them (removing any corruption) the next time it starts. You won’t lose your extensions or their settings by deleting these files.
Open your profile folder:
Click the menu button, click and select the menu, select. The Troubleshooting Information tab will open.
Under the Application Basics section next to Profile FolderDirectory, click Open FolderShow in FinderOpen Directory. A window will open that contains your profile profile folder will open.
Click the Firefox menu and select the Firefox menu at the top of the screen and select the Firefox menu and select.
Delete the following files:
(if found)
Restart Firefox.
Another installed extension may interfere with the installation of new extensions. Install the new extension in Firefox Troubleshoot Mode as a workaround.
These fine people helped write this article: AliceWyman, Underpass, Thomas, Tonnes, Michele Rodaro, Michael Verdi, Ricky Rosario, scoobidiver, Swarnava Sengupta, ideato, user669794, Lan, Joni, Artist, andrewtruong, Caitlin Neiman, Fabi
Volunteer
Grow and share your expertise with others. Answer questions and improve our knowledge base.
Learn More
Fix: Firefox Addons not Working – Appuals.com
The Firefox add-ons might not work if your Firefox browser is not up to date. Moreover, incorrect date/time settings of your system or corrupt Firefox user profile (or any of its settings/files) may also cause the user encounters the issue when he launches Firefox and the browser launches but either without addons (icons do not show) or the addons do not work at all (for some of the users, the issue was limited to some addons). The issue is reported on nearly all the major operating systems, usually after a Firefox refox Addons Not WorkingBefore moving on with the solutions to fix the Firefox addons, restart your system to rule out any temporary glitch. Moreover, make sure the addons are activated in the addons menu of the Firefox browser. Last but not least, do not forget to update your Firefox browser to the latest lution 1: Re-enable the Firefox Add-onsThe addons issue could be a result of a temporary glitch in Firefox. The glitch can be cleared by disabling and enabling the Firefox addons and thus solve the problem. This action re-initializes all the add-on modules and starts them the Firefox browser and open its menu by clicking on the hamburger menu near the top right of the, in the menu shown, click on Addons and then disable every addon by toggling its respective switch to the off Add-ons in the Firefox MenuThen enable the addons and check if the addons issue is resolved. Disable/Enable Firefox ExtensionsIf not, then install another addon to check if Firefox is working fine. You can also download the Firefox addon through another browser (preferably Chrome) and then drag-drop the addon to Firefox to check if the addon issue is not, then try to launch Firefox in Safe Mode and remove any of the problematic extensions (you can also remove all the extensions) there to check if they were causing the Start in Safe Mode to Confirm Firefox Safe ModeSolution 2: Correct Date and Time of Your SystemThe date and time of your system are used for many operations (like syncing of different services) by different applications. You may encounter the error at hand if the date and time of your system are not correct which in turn conflicts with Firefox’s own internal date-time engine. In this scenario, correcting the date and time of your system may solve the on the clock (shown in your system tray) and in the resulting menu, click on Adjust Date/justing date/timeNow, disable the options of Set Time Automatically and Set Time Zone click on the Change button (under the option of Set the Date and Time Manually) and then adjust the date and set the correct Time Zone of your system and then check if Firefox is clear of the nually Adjust Date Time of Your SystemIf not, then try to set the date of your system to one day back and check if the issue is even moving one day back doesn’t work, then try to set the date to the correct one and check if the Addons issue is lution 3: Disable Firefox PreferenceThe Firefox preference (when enabled) is used for disabling all the out of process extensions. You may encounter the error at hand if, due to a glitch, Firefox “thinks” all the extensions as out of the process. In this case, disabling the said preference may solve the the Firefox browser and key-in the following in the address bar:about:configNow click on the button to Accept the Risk and the Risk and Continue to Open about:config Menu of FirefoxThen search for the following preference in the Search Preference Name moteNow, click on the toggle switch to change its value to False (if True) and then relaunch the Firefox browser. Disable moteUpon relaunch, check if the Firefox addons are operating lution 4: Remove the Toolbars and Buttons CustomizationUsers tend to customize toolbars and buttons as per their requirements but this customization may lead to the current addons error. In this case, restoring toolbars and buttons to the defaults may solve the the Firefox browser and click on the hamburger menu (near the top right of the window) Customize in the Firefox MenuNow, in the menu shown, click on Customize and then, in the resulting window, click on Restore Defaults (near the right bottom of the window). Restore Toolbars and Buttons in Firefox to DefaultsThen check if the Firefox addons are working lution 5: Disable Dom Storage of FirefoxDOM Storage provides a way to use a more secure, larger, easier-to-use alternative for storing the information in the browser cookies. The Firefox add-ons might not work if the Dom Storage of Firefox is in an error state which in turn blocks the operation of add-ons. In this case, disabling the Dom Manager may solve the Firefox and in its address bar, type:about:configThen confirm to Accept the Risk and, type the following in the Search Preferences Name eDOSDevicePathSyntaxThen click on the toggle switch to change its value to False (if already True). Disable eDOSDevicePathSyntaxNow relaunch Firefox and check if it is clear of the addons lution 6: Enable History in the Firefox OptionsFirefox has a bug in which it may disable addons if remembering history is disabled. In this scenario, enabling the remember history option may solve the the Firefox browser and open its menu (by clicking on the hamburger menu near the top right of the window) Firefox OptionsNow, in the resulting menu, select Options and then, in the left half of the window, select Privacy & scroll down and in the History section, expand the dropdown of “Firefox Will”, in the dropdown, select Remember History and then check if the issue is Remember History in FirefoxSolution 7: Edit File to Allow Addons OperationFirefox add-ons may not work if entries in the file are not properly configured (that may stop addons from working). In this case, editing the file to let the addons operate may solve the Firefox and in its address bar, type:about:supportNow, in the Applications Basics table, click on the Open Folder button (in front of Profile Folder) which will open the Profile folder in the File Explorer of your Profile Folder of FirefoxNow, minimize the Profile folder and exit Firefox. Also, make sure none of the Firefox related processes are running in the Task Manager of your, switch to the Profile folder and open the file with your preferred text editor (e. g. Notepad, etc. ) in Firefox Profile FolderNow press Ctrl + F keys to open the search box and search for appDisabled. Then change all of its values to False (if True) Off appDisabled in extensions. jsonThen search for signedState and change its value to 2 (if set to 1) Off signedState in Extensions. jsonNow save and close the Extensions restart your system and upon restart, launch Firefox and check if its addons are clear of the not, then disable/enable add-ons one by one and check if the issue is lution 8: Remove All Files from Storage Folder of the Firefox User ProfileYou may encounter the error under discussion if the profile storage of Firefox is corrupt. This usually occurs after a bad update or when your operating system files are moved. In this case, deleting all the files from the Storage folder of the Firefox user profile may solve the problem (the files will be recreated on the next launch of Firefox) Firefox and type about:support in its address, in front of the Profile Folder (in the table of Applications Basics), click on the button of Open, minimize the Profile folder and close the Firefox browser (make sure not Firefox related process is running in the Task Manager of your system) switch to the Profile folder and then open the Storage Storage Folder in the Firefox Profile FolderNow delete all of the contents of the storage folder and then restart your the Contents of Storage Folder of Firefox ProfileUpon restart, launch the Firefox browser and check if its addons are working lution 9: Delete Extension Files from the Firefox User ProfileAdd-ons may also fail to work if the file storing the extensions registry is corrupt. In this scenario, delete the extensions from the Firefox user profile may solve the problem (do not worry, files will be recreated on the next launch of Firefox) the Firefox browser and in its address bar, type:about:supportNow scroll down and in the table of Application Basics, click on the Open Folder button in front of Profile Folder (which will open the Profile folder window in the File Explorer), minimize the Profile folder window and close the Firefox browser (make sure no Firefox related process is running in the Task Manager of your system) switch to the Profile folder window and delete all the extensions files All the Extensions Files in the Firefox Profile FolderNow delete the file and then restart your File in the Firefox Profile FolderUpon restart, launch Firefox and check if the addons issue is lution 10: Create a New Firefox ProfileThe Firefox add-ons might not work if your user profile of Firefox is corrupt. In this context, creating a new user profile may solve the problem. Before proceeding, make sure to backup essential information/data of the Firefox browser and its a new Firefox user, check if the addons issue is resolved. If so, then you can copy the to the old profile to check if it was causing the lution 11: Refresh FirefoxThe addons issue could be a result of a conflicting addon or misconfiguration of a setting of the Firefox browser. In this context, refreshing the Firefox browser (that will remove all the addons/customizations and restore the browser settings to their defaults) may solve the problem as there isn’t any other way we check for the integrity of the application the Firefox browser and click on the hamburger click on Help and then click on Troubleshooting Troubleshooting Information in the Help Menu of FirefoxThen, in the window shown, click on the Refresh Firefox button and then confirm to refresh the Firefox fresh FirefoxNow, after refreshing the browser, check if Firefox is operating not, refresh Firefox (as discussed above) and then enable the option of Remember History (if disabled) as discussed in solution 7 to check if the issue is lution 12: Change the Certificate Requirement of AddonsFirefox browser may not operate add-ons if the certificate required (add-ons require a certificate to operate so that the malicious add-ons could be curbed) for the add-ons is corrupt or expired. In this case, disabling the certificate requirement of the add-ons may solve the problem. Warning: Proceed at your own risk as disabling the certificate requirement of addons may expose your system to malicious addons and can be a threat to your system/ the Firefox browser and type about:config in its address Accept the Risk and, search for quired in the Search Preference Name and then click on its toggle switch to change its value to False (if True). Disable quired in FirefoxThen relaunch Firefox and hopefully, the addons issue is the issue is there, then try to use debug mode of Firefox (type about:debugging in the address bar and then click on This Firefox. Now click on the Load Temporary Add-ons to use the addons temporarily). Load Temporary Add-on FirefoxYou can also try to copy the Mozilla folders from%appdata% and%localappdata% of a working installation of Firefox to the problematic system.
Kevin is a dynamic and self-motivated information technology professional, with a Thorough knowledge of all facets pertaining to network infrastructure design, implementation and administration. Superior record of delivering simultaneous large-scale mission critical projects on time and under budget.
Frequently Asked Questions about firefox extension download failed
Why can’t I download extensions on Firefox?
If your installed version of Firefox does not fit within that range, installing the add-on results in an error, indicating that the add-on is not compatible. If your version of Firefox is incompatible with the add-on, you can: Update to the latest version of Firefox. … Use a different extension.
How do I fix Firefox download failed?
How do I fix Firefox download failed?Check the Downloads panel for blocked downloads.Clear the download history.Choose a different download folder.Reset the download folder.Change file type settings.Configure Internet security software.Other solutions.Jun 1, 2021
Why are Firefox extensions not working?
The Firefox add-ons might not work if your Firefox browser is not up to date. Moreover, incorrect date/time settings of your system or corrupt Firefox user profile (or any of its settings/files) may also cause the issue. … Moreover, make sure the addons are activated in the addons menu of the Firefox browser.Sep 17, 2021
