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
Note that this UI in Xcode is a convenience and shouldn't block your work. The profiles you'd like to download are still available following these steps:
At this point, your profile will be installed on your Mac and usable within Xcode.
For the OP — if manually installing the profile this way didn't resolve the issue, then you're likely seeing another configuration problem or a bug. Could you clarify what you saw after you manually installed the profile and selected it in the General tab — did you get a build error or other issue?