guys, any idea on how to fix this very issue, but not only with FB, but with Mail app itself?
It simply keeps telling me to set up a new account, though I still have them in Accounts and I`m able to set them all online (FB, Gtalk, Skype) with red icon...]
but there`s no mail notification or anything since yesterday`s OTA update and trouble with N9QuickTweak app...
I flashed it today with NaviFirm, re-installed it with NSU, no change whatsoever...
the phone still acts strange...

also, I can see my pictures in Filebox (Pictures) but Gallery app is still empty...?
THX