succumb means to give into or be beaten by something accept means to put up with these are not quiet the same thing and, let's face it, succumb is not a word used much outside romantic novels or. I think Robin Hood would have succumbed to his wounds. "any longer" looks a bit out of place without some punctuation. So you could write "Few of us, any longer, accept such an error" but is still a clumsy sentence and I'm not sure what "any longer" is adding to the meaning, I might try "few of us accept such an error any more". In conclusion "any more" is better and the position needs to move.