"*": {
   "blocked_install_message": "Extension is not whitelisted. Please contact IT Support",
   "install_sources": ["https://addons.mozilla.org/"],
   "installation_mode": "blocked"
 }

   "[email protected]": {
   "installation_mode": "allowed",
   "install_url": "https://addons.mozilla.org/en-US/firefox/addon/lastpass-password-manager/"
 }

   "[email protected]": {
   "installation_mode": "allowed",
   "install_url": "https://www.dashlane.com/en/"
 }

Hi there, I'm attempting to configure group policy in my organisation to only allow the install of selected Firefox plugins present in our whitelist. I am doing this via the ExtensionSettings policy within the Firefox templates v1.14 I have successfully made the default behavior to block plugins, using this string: "*": { "blocked_install_message": "Extension is not whitelisted. Please contact IT Support", "install_sources": ["https://addons.mozilla.org/"], "installation_mode": "blocked" } I'm even able to successfully whitelist plugins on the mozilla addon page, example below: "[email protected]": { "installation_mode": "allowed", "install_url": "https://addons.mozilla.org/en-US/firefox/addon/lastpass-password-manager/" } My problem is I can't seem to whitelist any plugins that are installed from any source other than Mozilla. For example, Dashlane is only available via their website. I tried the following, but it still says blocked. "[email protected]": { "installation_mode": "allowed", "install_url": "https://www.dashlane.com/en/" } I have run into the same issue with another plugin, even when using the full URL of the .xpi file. I've played around with this for a good few hours, but nothing seems to work. Any advice? Thanks in advance.