Firefox Community Forum

Application error: a client-side exception has occurred while loading (see the browser console for more information).

where is the browser console? how do i fix it never had an issue with until the last two days?

Greetings Ya'll,

I have to apologize if this is a double post, but I came back to the forum, & wanted to see if there were any responses, but i could only find my post listed under "My Profile"/"My Questions".

My original post was made Dec. 19-2025

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Early this morning as I went to use the Firefox browser, on My Desktop, I got an update, & then firefox opened, somewhat.

The homepage did not fill in with favorites, suggestions, etc, and in fact all that did load was the Search bar, but not one of my usual website buttons. The "edit", "help", etc. buttons at the upper left hand corner did load, but that is all. Not one of the buttons work, nor can I close out the Firefox page, by tapping the "X" in the upper right hand corner.

The only way that I could close out the "Firefox Page" was by going through the "Control/Alt/Delete" & then "Signing Out", which would initiate a "Re-start". Once I signed in, I could return to the Desktop, where everything works.

I use Firefox as my Browser on my Android phone, & at this moment, I've not had any problems using Firefox on my Cell Phone.

The only way that I could get to the Mozilla Website was by using the Microsoft Edge Browser, which is not giving me any problems as far as accessing the Internet!

How can I correct this problem, & go back to the Firefox Browser?

Through extensive troubleshooting, I am unable to get firefox to open at all.

I've done a full uninstall, cleaned all user directories, program files / x86, program data, appdata roaming and local, etc. I used the Microsoft uninstaller and even Revo Uninstaller to remove everything related to Firefox, did a restart and reinstall of the latest one and it still won't launch.

Firefox was previously working until a reboot occurred and now it won't launch.

Firefox 32 bit seems to work when installed, and running Firefox as an admin previously worked but no it no longer does.

I looked at the following articles: - https://support.mozilla.org/en-US/kb/firefox-wont-start-find-solutions - https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles - https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles#w_start-the-profile-manager-when-firefox-is-closed

There's no malware on this machine (business EDR on it, even disabled it as a test and it still didn't open).

I was able to launch the profile manager but now I am unable to as the processes launch in task manager and then within 5 seconds they close.

Firefox is not running in the background for any user (I'm the only one logged in after a reboot as well)

I'm unable to open in troubleshoot mode either. Tried run as and admin cmd "C:\Program Files\Mozilla Firefox\firefox.exe" -safe-mode

Ran SFC / scannow / DISM restore health commands as well and both came back fine / no integrity violations

Restarted W10 pc. Firefox is set to open on restart open previous tabs. Firefox did not open. Cannot open Firefox application manually. Running Ironscales and Sentinel One on PC. Running Privacy Badger on Firefox. Firefox was slow opening pages yesterday. I thought it was my INET connection.

When I turn on my Mac and click the Firefox browser icon, it will not load. It hangs. I get a "not responding" message and have to "force quit," again and again until FINALLY it loads, after five or more failed attempts. This does not happen with Firefox on my laptop, only my Mac. Both Firefox and my Mac are up to date. Why is this happening? Please help. It happens every day when I try to load the browser. I am about to give up and move to Safari. Relatedly, anyone know if it's possible to export all my bookmarks from Firefox to Safari?

Actually this is just the only route I could figure out to your page where I had PREVIOUSLY asked this question and was checking back in to see whether 'the Community' had given me an answer yet. I'm no doubt IMPATIENT since my bank told me I need you, not Google and Microsoft Edge , who I both HATE for coming on to MY laptop, asking for more information sharing and basically DEMANDING I follow their marketing instructions since they had somehow REMOVED the X at the top right corner and simultaneously BLOCKED my access to and use of my OWN laptop, so that each time I have NO OPTION but to turn off the power on my laptop, to "reboot" as they once said. If even a basic, ancient telephone can be HUNG UP on scammers.....forgive me. I REALLY want to use your search engine, as WELL as your site. Please advise.

I have made multiple efforts to download Firefox onto a recently acquired laptop but it doesn't launch.

The laptop is a Dell Latitude 5520 running Windows 11 Pro.

I have on several occasions downloaded Firefox.exe (version 146.0.1.763), double clicked to start it, clicked to approve that the app can make changes and watched as the installation graphic fills and I get confirmation that installation has completed. Then nothing.

I have uninstalled the app and started again. No change.

The app appears in the list of apps (I have successfully made Firefox the default browser) but I don't know how to launch it.

I would be grateful if someone could provide the solution!

M

Firefox does not start automatically when Windows 11 starts. When I do start it manually, then a small rectangle appears on the screen in the upper left corner of the screen!

Please address issues.