This reminds me I have to see what's up with my install. Tried running earlier and got a message that it's secure store is busted, and have options to switch profile or continue and lose data, and all profiles are similarly broken. Luckily I don't keep much in it beyond sites like GMail and anything else not very Firefox friendly. Hoping this doesn't mean I lose access to my Google account as it's only logged in there.

I'm the kind of person who reinstalls linux to change distro and copies over my installation folder for my browser. A long time ago (back when it released in 2014/5) I would do this with windows too. Usually I would get to keep my browser perfectly intact, tabs and all.

That's harder on Linux, with Windows I usually had to only copy appdata for the user and everything would be flawless. I don't know exactly what's different with Linux Vivaldi installs, but it almost always breaks like this.

There are Singleton lock files in .config/vivaldi[-snapshot] that can be deleted if the profiles aren't protected by a keyring.

If the profiles are protected by either KWallet or Gnome-libsecret, you need to unlock that keyring before starting Vivaldi. If you moved to a KDE or Gnome desktop environment from something like Niri or Hyprland, or vice versa, this can happen.

With Vivaldi closed, back up ~/.config/vivaldi/ or ~/.config/vivaldi-snapshot, then try launching with the original backend:

vivaldi-stable --password-store=kwallet6

vivaldi-stable --password-store=kwallet5

vivaldi-stable --password-store=gnome-libsecret

vivaldi-stable --password-store=basic (only if the original profile used it; not recommended for regular use) I had to do this when I went from Hyprland to KDE Plasma and KDE Wallet made it so I couldn't open Vivaldi when I logged into the Hyprland session.

For KWallet/libsecret, the original wallet must also be available and unlocked.

I had the same thing when I switched from Gnome to Niri. In the end I got it fixed somehow, but I don't remember the exact details.

It was about how the default keyring was called, and that the name of the keyring ia actually case sensitive.