Yes, that is a much safer way, instead of messing with the registry each time.
And it works in Linux as well (not that I expect MS to push this cr*p to my main OS).
I have now put this inpolicies.jsonand it worked:
Code:{ "policies": { "ExtensionSettings": { "*": { "blocked_install_message": "This extension has been blocked by your administrator." }, "{8d8ca802-6b23-43ed-9445-e05d48579542}": { "installation_mode": "blocked" }, "{a07b7886-3015-4959-9a88-4273860edd6d}": { "installation_mode": "blocked" } } } }
Yes, I notice you've added another policy for the second,in my opinion, unlikely,extension because it doesn't match the one for Chromium-based browsers.
If you want, you can also omit the optional opening part; as my screenshot shows, the policy works just the same.
I'll include my JSON file here, which, as you can see, contains four policies in abbreviated form,this should also be helpful to other forum users
Code:
{
"policies": {
"OverridePostUpdatePage": "",
"DontCheckDefaultBrowser": true,
"OverrideFirstRunPage": "",
"ExtensionSettings": {
"{a07b7886-3015-4959-9a88-4273860edd6d}": {
"installation_mode": "blocked"
}
}
}
}
Note that, in my case, if I were to add a fifth policy, I would have to put a “,” after the last policy.

