topic Another copy of Firefox has made changes to profiles. You must restart Firefox before making more changes. in Discussions

Another copy of Firefox has made changes to profiles. You must restart Firefox before making more changes.

benjaminclewis — Mon, 22 Dec 2025 21:46:38 GMT

I've been using what I gather is an "older" profiles system via about:profiles.

Now if I go to about:profiles and open my second profile in another window, close it, and then open about:profiles again in first window, I get "Another copy of Firefox has made changes to profiles. You must restart Firefox before making more changes."

This happens every single time, even though I've made zero changes to profiles, and is extremely annoying.

Can/should I migrate my profiles to the new profile manager? How to do this?

Re: Another copy of Firefox has made changes to profiles. You must restart Firefox before making more changes.

siffemcon — Tue, 23 Dec 2025 01:32:42 GMT

Support requests aren't allowed here. Please post your question with full details at https://support.mozilla.org/en-US/questions/new/firefox.

Re: Another copy of Firefox has made changes to profiles. You must restart Firefox before making more changes.

sid2 — Fri, 13 Mar 2026 13:35:29 GMT

I have exactly this problem with 148.0 and it's extremely annoying. I'd move to the new system of profiles but that seems risky/complicated. About to update to 148.0.2 see if that helps.