George R. R. Martin is having a rough time with The Winds of Winter because he accidentally killed an important character

So apparently George R. R. Martin is having a rough time with The Winds of Winter because he accidentally killed an important Game of Thrones character. As he put it in an interview, "I’m having all kinds of trouble...You ever killed somebody off that you later realized you knew you needed?"

Had I been the interviewer, I might have answered, "Well, Mr. Martin, no, and even as a Fantasy writer myself I have trouble imaging how you quite managed to pull that off. Then again, if you insist in killing off characters to the point that Westeros and slaughterhouses have a lot in common then yes, I suppose I can see how you accidentally butchered a cow-- I mean character whom you intended to keep. Valar morghulis, as they say. For myself and other non-Grimdark authors, we try not to kill off many characters in general, much less one we even vaguely suspect we might need in the future."