I recently updated to Xcode 8 and as I click on \"download\" option next to provisioning profile in Xcode/Preferences/Accounts/View Details menu it changes to gray and does not
The answer is here.
Its doesn't sound much but it really worked for me.
Just right click on the provision profile and click on Show in finder. Then delete all the provision profile in the entire folder.
Not goto Xcode project settings and Check the checkbox, Automatically manager signing. The xcode will do the rest for you.