if I ever go back to chrome, this dialog will be the reason why

Since people keep asking:
This is on the latest version, and I'm on Windows.
They got rid of this on some platforms/configurations, but it still exists for others.

I think specifically this is happening because I'm making the mistake of trying to use Firefox's multiple profile support

multiple profile support is one of those features I always get the feeling mozilla would like to get rid of. It's always hidden and slightly annoying to use... but it never goes away
@foone didn't they make a new, more visible ui for profiles a few versions ago?
@rnd @foone they did, I've been using multiple profiles since then. very useful, very nice
@_r @rnd @foone … what is said UI? i still have about:profiles bookmarked for quick access, i don’t think it’s particularly visible otherwise
@domi @foone @rnd context menu top right, click on your profile, from there you can either switch or manage profiles. interestingly, these won’t show up in about:profiles even though they are profiles, will make folders in the profiles folder, and are usable via --profile. by all means, they’re profiles, they just don’t get written to ~/.mozilla/firefox/profiles.ini

@_r Ooh, interesting! I note the opposite is true as well: profiles created through the old UI don't show up in the new list.

I wonder if you can "upgrade" by using the "Copy Profile" option in the new UI while in an "old style" non-default profile...

@_r Oh wow, apparently the list of new-style profiles is stored... inside your profile!

*insert "Yo Dawg" meme here*

@imsop what the fuck. what idiot came up with this?

is it… the main profile? or is it duplicated in every profile?

@_r Ah, I may have spoken too soon; they're *tied to* a primary profile, but not actually *inside* it.

There's a new "Profile Groups" folder, which is a bunch of SQLite DBs, because text files are sooo last century. Looks like a "StoreID" key in profiles.ini is used to bootstrap from the old system to the new one. So migrating might require a little more hacking.