> Nope, it only happens when something outside changed Firefox's files … This never happens* in Windows and macOS (it might nag, but you can definitely dismiss it).
Happens with multiple Firefox instances too, `firefox -P -no-remote` (I think in recent versions the -no-remote is redundant), even on Windows with official installers. In that case you don't even get the error message; new tabs just remain blank. There might be a delay between process A's update and symptoms appearing in process B; not sure.
Happens with multiple Firefox instances too, `firefox -P -no-remote` (I think in recent versions the -no-remote is redundant), even on Windows with official installers. In that case you don't even get the error message; new tabs just remain blank. There might be a delay between process A's update and symptoms appearing in process B; not sure.