hi, in this case i'd suggest running a scan with multiple different security tools like the free version of malwarebytes, adwcleaner & eset online one-time scanner.

See if Firefox will start in the diagnostic Safe Mode. Hold your computer Shift Key down as you click on the Firefox icon.

philipp said

hi, in this case i'd suggest running a scan with multiple different security tools like the free version of malwarebytes, adwcleaner & eset online one-time scanner.

Philipp, thank you for your suggestions. I scanned the hdd with several tools but no serious threats were found. Another suggestion?

alan_r said

See if Firefox will start in the diagnostic Safe Mode. Hold your computer Shift Key down as you click on the Firefox icon.

Alan, thanks for your suggestion. I tried to start Firefox in safe mode, but even that did not work. More suggestions?

Hi, there has been a few instances of FF not starting after the v56.0.1update which installed 64-bit FF. This seems to be caused by an incompatibility with a Logitech camera. If you have one, try disabling or updating any software.

You can instead try downloading the 32-bit version of FF from https://www.mozilla.org/en-US/firefox/all/

If none of the above applies try performing a Clean reinstall. This means you remove your Firefox program files and then reinstall Firefox. This process does not remove your Firefox profile data (such as bookmarks and passwords), since that information is stored in a different location.

To do a clean reinstall of 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 mozilla.org (or choose the download for your operating system and language from this page) and save the setup file to your computer.
2. After the download finishes, close all Firefox windows (or open the Firefox menu and click the close button ).
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 use a third party uninstaller as part of this process. Doing so could permanently delete your Firefox profile data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be easily recovered unless they have been backed up to an external device! See Back up and restore information in Firefox profiles.

Please report back to say if this helped you!

Thank you.

hampet47 said

Hi, For some time Firefox does not start anymore. No error message, no crash, nothing happens. I tried to find any information about this problem on Firefox help pages, but did not find anything usefull. I tried a complete uninstall of Firefox with Revo Uninstall and reinstalled the newest version. Not any result. Still the programm does not start at all. The OS is Windows 10. Please can anybody give me some suggestions how to fix this problem?

Scribe said

Hi, there has been a few instances of FF not starting after the v56.0.1update which installed 64-bit FF. This seems to be caused by an incompatibility with a Logitech camera. If you have one, try disabling or updating any software. You can instead try downloading the 32-bit version of FF from https://www.mozilla.org/en-US/firefox/all/

---

If none of the above applies try performing a Clean reinstall. This means you remove your Firefox program files and then reinstall Firefox. This process does not remove your Firefox profile data (such as bookmarks and passwords), since that information is stored in a different location.

To do a clean reinstall of 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 mozilla.org (or choose the download for your operating system and language from this page) and save the setup file to your computer.
2. After the download finishes, close all Firefox windows (or open the Firefox menu and click the close button ).
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 use a third party uninstaller as part of this process. Doing so could permanently delete your Firefox profile data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be easily recovered unless they have been backed up to an external device! See Back up and restore information in Firefox profiles.

Please report back to say if this helped you!

Thank you.

Thank you for this real unbelievable sollution. I downloaded and installed the last version software for the Logitech camera and Firefox start again. I appreciated your help!

It's 4/26/18 and version 59, just got the same problem as on top. I do see firefox started in TASK Manager but that is the only place, nothing on screen or indication it is running. Using Edge to respond in Support. I did the uninstall and reinstall as described but get nothing even with that. Have no idea what to do next, except to keep using EDGE!! Help please??