i run launched again the firefox and got the same error pop-up.

used the kill xxxx command, but it killed the error pop-up. i think
there are now missing files in the firefox but not sure what. as i
have done the reinstall earlier but to no avail.

btw, the error pop-up is like this in the command line:

/usr/lib/firefox/firefox-bin

when i killed this process, the error pop-up is shutdown.

what should i do next. and thanks.