I asked the same question for version 64.0, and the then accepted answer worked. For the 66.0.5 (64-Bit) version on Windows 7 Home Premium it doesn't work anymore.
I had to install the 66.0.5 version, I did it by downloading the installation file (xx MegaByte) and starting it locally. It deleted the distribution-folder. I recreated it and the policies file.
But today I got the update nag screen again, asking me to update to Firefox 67.
How to stop in version 66.0.5 (64-Bit) on Windows 7 Home Premium the update nag screen?
(And how to stop Firefox to contact the Mozilla servers for checking for new versions?!!!)
Would
{
"policies": {
"DisableAppUpdate": true,
"AppUpdateURL": "https://0.0.0.0"
}
}
in the policies.json file help?