I can't remember my old passcode

In my settings it says Update Apple ID Settings - Some account services will not be available until you sign in again. I go through and enter my Apple ID password and my current iphone password then it asks for my old password. I had to reset my phone because I forgot my password. So I press Forgot Iphone passcode. Then it says that I can press Reset Encrypted Data or Cancel. I don't want to Reset encrypted data but I also want this pop up to be gone. Whenever I press Cancel it all ways pops up again a few weeks/months later. How do I approve my device from one of my other devices signed into icloud?

Help!