Thanks for updating it so quickly!
It is indeed working now, but not always. I haven't been able to find the exact problem, but depending the websites I have opened, sometimes the workflow doesn't find any tabs via Alfred.
It doesn't matter if they are open in chrome or safari. For example, www.elotrolado.net or www.elmundo.es. If any of this webpages is loaded in a tab, the workflow won't return any result, but if they aren't the workflow will work just fine.
I haven't been able to find what could be wrong with this websites.
If I launch the ruby script myself via /usr/bin/ruby