This is Firefox 142.0.1 on Windows 10. I prefer to have a local copy of the Firefox profile saved to a USB stick as a simple backup and for copying to another PC if necessary. I have been doing this for years, but now I am unable to do so because Windows gives me an "access denied" error for all of the files in the top-level profile directory. I cannot even open them in Administrator mode. If I try to copy the profile directory as described in your help pages, it says that I need permission from the account that I am logged in as in order to access the files! I have been using Windows since version 3.0 and I cannot understand what Firefox has done to make the profile inaccessible to everything but itself. Obviously, Firefox is able to read the files without additional permissions, so why can't I?