Your question is not clear enough to give a good answer, which phone you talk about and is it carrier branded or not.
For Lumia phones see this link https://forums.windowscentral.com/e...pdate%2Fwp8-software-update%2F&token=P0BT-VMH
If you have another brand check the website of the manufacturer.
If you use Preview For Developer unmark the box in the app and check again.
If you need further assistance please register and reply on this post.