are you using any extensions that might interact with the content of the webpage?

hi madperson! thanks for your prompt reply.

how to know it? i did not update any extension before it crashed, unless it was automatically.

I guess it can be due to Zotero...do you know this ? But do not know if I can uninstall it since I have info inthere.

Nieves

in order to diagnose the issue, can you please launch firefox in safemode once and see if the error message is occuring there too. if not, then please try disabling all of your extensions in tools > addons > extensions, restart the browser and reenable them one-by-one in order to find out what has caused this (a restart might be necessary after each step).

i'm not sure if i understood this correctly, but if the whole browser crashed you might also be able to retrieve a crash id, that would help use in troubleshooting the issue better.

hi again, you were right, it was not Zotrero but an extension named Scholar H-index calculator that made occur this error. Firefox did not crashed, actually, a pop up window appeared saying the error in this variable refine all was null.

thanks for your indications

ok, glad you could figure out the cause of the error message. you can also report the issue to the author of the extension, he is the one who can fix it. there's a support mail adress provided at https://addons.mozilla.org/firefox/ad.../scholar-h-index-calculator/

you have been very useful, thanks mad ;)

This posting was extremely helpful to me. Yes, it was scholar-h-index-calculator that was causing the error statement.