The first one is correct and the second one doesn't make sense. This 〜からでなければ is like "after (finishing) doing ..., you'll be able to do ..." (first you should do ... , then you have a permission for something).
For example, "after finishing your homework, you can watch the TV / if you don't do your homework, you can't watch TV". (宿題を終えてからでなければテレビを見てはいけない / 宿題をしないならテレビを見てはいけない。= 宿題が終わったらテレビを見ても良い。) *The literal translation doesn't work well in my opinion.
I think my explanation is incomplete, however, I hope this was helpful.