Firefox "Web Filter" issues please!

My laptop is Win 7 Professional and existing Firefox ver. is 40.0.3 (just been upgraded). I did not use FF much but using IE generally. I received a prompt from FF V30 suggesting that I should do some kind of RESET to speed things up when I was attempting to run FF ver 30 this morning.

I ignored it and continued to open FF. All of a sudden I could not reach MOST of the web-sites any more but kept receiving a warning from FF that "The Web Page you have tried to visit could not be checked by the Web Filter" and suggested I should carry out the internet access for further 20 minutes to restore some kind of histories in the Filter. Of course it does help even I had un-installed FF V30 and re-installed with FF V40.0.3 afterwards .
So my question is "what is FF's Web Filter" and HOW to restore my FF V40 back to normal please??? Or is it something even more serious??

Many thanks

Edited by deleted (Tue 22-Sep-15 16:47:34)

Is that NetIntelligence?

You were absolutely right! I was also feeling suspecious too about "Filtering" BEFORE I read your suggestion!
I ended up with uninstalling my Netintelligence SW and everything is then becoming O.K as it used to be!!

Thanks for your suggestion!

I nearly always use FF with NoScript and AdBlock+.

Lately it won't work with NatWest online banking, as soon as I try an input the webpage freezes,
it does eventually recover, but it's quicker to shut it down and restart !
It seems to have something to do with chat.nwolb.com, which is trying to load it self on to my computer.
Script shows only websites by No's, haven't worked out which ones...
Anyone knows what is going on, andhow to fix it....?
Thanks, regards,
Martin