page not found오류가나네요(카테고리 글쓰기)

글을 쓰려고 버튼을 누르면 이런 오류가 나요(다른것은 잘됩니다)

Using the URLconf defined in config.urls, Django tried these URL patterns, in this order:

admin/
board/ [name='index']
board/ / [name='detail']
board/ question/list// [name='question_list']
board/ detail/ [name='qna']
board/ question/create/ [name='question_create']
board/ question/modify// [name='question_modify']
....생략