Hi James

Did you install Firefox from the Windows app store?

Note that AppDate is a hidden folder.

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page (Root directory).

• Help -> More Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

Firefox MSIX from the MS Store has the profile in this location:

• C:\Users\xxx\AppData\Local\Packages\Mozilla.Firefox_xxxxxxxxxxxxx\LocalCache\Roaming\Mozilla\Firefox

Hi James Did you install Firefox from the Windows app store?

Long story short: Download Firefox from the website and NOT the Microsoft app store. The file path location from the app store is garbage, confusing and fraught with permission errors and hidden folder/files. In the end, I never could find it. I just uninstalled, deleted everything I could find with the words "Mozilla" and "Firefox" and then reinstalled from the website.

TL/DR: Do yourself a favor if you're reading this and download Firefox from the website like a normal human being, not from the app store like me. Thanks for pointing me in the right direction Paul.

- James

Why do you need to access the installation folder?

The Microsoft Store package (MSIX) is more restrictive but has better security.

I think the issue is mainly the missing default folder structures when using the store installation.

I am using 3 different profiles work, private, entertainment I copied the profiles from here

  C:\Users\user\AppData\Roaming\Mozilla\Firefox\Profiles

to a new machine.

  C:\Users\newuser\AppData\Roaming\Mozilla\Firefox\Profiles

On the new machine in the about:profiles I then created 3 new profiles using the previously copied folders. that worked fine!

Further investigation shows:

In the installed package from the store C:\Users\JohnDoe\AppData\Local\Packages\Mozilla.Firefox_xxxxxxx\LocalCache\ we find a localized instance of %AppData%\Roaming\Mozilla\Firefox\Profiles

Creating a symlink to the standard documented location causes firefox to hang. Well, its Microsoft. It never works intuitively. Redmond chose this path decades ago!

I wonder about the man years of workarounds they had to invest over the last decades, because of the weird design approaches they chose in the beginning, and had to support for backward compatibility over the years. Well why do it simple when we can do it our own way..... I am not a fan since the 80ies for the mess they created, it works OK now, but look at the size of the system... its called bloatware! "

So for the Appstore installation, there is the some well-known secret Microsoft magic in place which seemingly creates a boxed execution environment. But a symbolic link to the profile folder in the default location, which would work on any linux system does not work for Windows. Transparency was never their thing. Surprise!

So, yes, if you want to stay in control the right way is to use the original firefox installer and not the store!