Firefox Community Forum

Resolved Update: apparently cat cannot write to /etc. Resolved by using:

sudo tee /etc/apt/sources.list.d/mozilla.sources <<eof types: deb uris: https: packages.mozilla.org apt suites: mozilla components: main signed-by: etc keyrings packages.mozilla.org.asc eof p></eof>

The instructions need updating!

_________________original problem (in case some one else needs the information)

I am following the instructions in section "Install Firefox from Mozilla Repository (Recommended)" at https://support.mozilla.org/en-US/kb/run-firefox-chromeos At step 4 I am receiving a permission denied error: "-bash: /etc/apt/sources.list.d/mozilla.sources: Permission denied" I am not sure how to resolve or continue.

Last command and output:

username@penguin:~ cat <<EOF > /etc/apt/sources.list.d/mozilla.sources Types: deb URIs: https://packages.mozilla.org/apt Suites: mozilla Components: main Signed-By: /etc/apt/keyrings/packages.mozilla.org.asc EOF -bash: /etc/apt/sources.list.d/mozilla.sources: Permission denied

I followed the advise and removed all the profiles from my laptop. (Copies are on an external hard drive.) And I used the download file from the Mozilla community site which is 490 KB versus the 375 KB download file from firefox.com just in case the smaller file was corrupted. But I still got the Profile Missing error message.

I am trying to simulate a laptop that has never used Firefox and so can't say that "Your Firefox profile cannot be loaded.  It may be missing or inaccessible."  I uninstalled Firefox using the Installed Apps page. Can there be fragments of Firefox that I need to hunt down and remove? I also removed the Old Firefox Data folder from the desktop.

How can I successfully install Firefox? Then I will use my old profiles that contain all my bookmarks.

bold textI downloaded fire fox but don't see it listed with my other browsers, why? i downloaded fire fox but it's not listed among my browsers, why?

The full winget command is: ```pwsh winget install --id Mozilla.Firefox.zh-CN -s winget -e -i -l D:/.../Mozilla/Firefox/ ```

The winget log mentioned that winget downloaded https://download-installer.cdn.mozilla.net/pub/firefox/releases/150.0.2/win64/zh-CN/Firefox%20Setup%20150.0.2.exe ```log 2026-05-12 22:19:28.840 [CORE] WinINet downloading from url: https://download-installer.cdn.mozilla.net/pub/firefox/releases/150.0.2/win64/zh-CN/Firefox%20Setup%20150.0.2.exe 2026-05-12 22:37:42.091 [CORE] Download hash: 6c7fb833ebb13637daf750c7a2c611e2b6d8d324dc2463eed40e8478d0c791fc 2026-05-12 22:37:42.091 [CORE] Download completed. 2026-05-12 22:37:42.094 [CLI ] Installer hash verified ```

Installer args: ```log 2026-05-12 22:37:43.543 [CLI ] Installer args: /InstallDirectoryPath="D:/.../Mozilla/Firefox/" 2026-05-12 22:37:43.545 [CLI ] Starting: 'D:\Temp\WinGet\Mozilla.Firefox.zh-CN.150.0.2\Firefox%20Setup%20150.0.2.exe' with arguments ' /InstallDirectoryPath="D:/.../Mozilla/Firefox/"' 2026-05-12 22:38:12.554 [REPO] Reading MSI UpgradeCodes 2026-05-12 22:38:12.891 [REPO] Reading MSI UpgradeCodes 2026-05-12 22:38:13.405 [CLI ] During package install, 1 changes to ARP were observed, 1 matches were found for the package, and 1 packages were in both 2026-05-12 22:38:13.405 [CLI ] The entry determined to be associated with the package is 'Mozilla Firefox (x64 zh-CN)', with publisher 'Mozilla' ```

Then winget shows the installation was successful, but the shortcuts in the Start menu and on the desktop point to a path that doesn't exist. I noticed that this path is the one I passed to winget via the -l parameter, but it is missing the slash (`/`) > D:/a/b/Mozilla/Firefox/ → D:\abMozillaFirefox\ I couldn't find the installed Firefox either in the root directory of drive D or under the originally expected path D:\...\Mozilla\Firefox.

Although I passed the -i parameter (specifying interactive installation) to winget, I didn't see the installer window. In the user registry, the installer also wrote the aforementioned incorrect path, and I cannot uninstall this installation through Windows Settings.

I wrote a script myself to search for folders or files with 'firefox' in the name (case-insensitive) on my system's C and D drives, and I only found this folder that looks related: ```pwsh > ls "C:\Users\...\AppData\Roaming\Mozilla\Firefox"

   Directory: C:\Users\...\AppData\Roaming\Mozilla\Firefox

Mode LastWriteTime Length Name

d---- 2025/11/23 18:05 Background Tasks Profiles d---- 2025/12/24 18:47 Crash Reports d---- 2025/11/23 18:05 Pending Pings d---- 2025/11/23 18:06 Profile Groups d---- 2025/11/23 18:06 Profiles -a--- 2025/12/27 8:43 75 installs.ini -a--- 2025/12/27 8:43 482 profiles.ini ``` But based on the LastWriteTime, this seems to have been left when I previously installed Firefox.

I want to know what the installer does after running the above installation, and how I can undo these changes to reinstall Firefox?

> Note: English is not my native language, please forgive my spelling or grammar mistakes. > I originally wanted to post on a Chinese forum, but I was guided here...

As my title says i cant move Firefox from desktop because it is *the* browser file not a shortcut, and every time i try to move it to any different folder it just creates a shortcut in said folder. I asked Copilot how to reinstall it, set it in actual search mode so i could have 100% reliable steps, nothing worked! >:ε

so im asking yall if there is a way to fix it, thanks in advance

Dear Sirs! I've been trying to install FF in several ways. Using installer.exe and setup150.exe. I started these files from same disk as the system (C), Temp folder empty and unlocked for read\write, located where it should be C-user-appdata-local-temp. I started files as administrator. Each time the setup fails with system notice like on the picture attached. It says "can not find specified file"

My notebook is very old, but it runs Win 10 OK, Chrome is OK also

Intel(R) Core(TM)2 Duo CPU P8400 @ 2.26GHz 2.27 GHz 4,00 Gb SSD 224 GB SSD P4-240 Mobile Intel(R) 4 Series Express Chipset Family (Microsoft Corporation - WDDM 1.1) (64 MB) x64 system

Please help!

The latest version of Firefox (installed today) just crashes when trying to open any tab and will not reload anything. How can I reload the last working version? Kind regards Stephen.

I don't think the install finished correctly I am sending this from Chrome.

Kind regards

Stephen

I can't install Mozilla VPN on MacOS 10.15.8. The installation programm tell me to ask for help to the editor of the VPN... I'm afraid that it's possible there is NO version available for my old machine... Am- I right ?