Xcode 8 signing errors, can't login with account and no provisioning profile

I can't take credit for this solution, it came from BrianBatchelder on the apple forum.

I had to go to "XCode" -> "Preferences" -> "Accounts", where it turned out my Apple ID had timed-out. After logging-in there, and then restarting Xcode, my profile was automatically "repaired", and all is now well.

Re-starting Xcode is important there, it doesn't work without it.

I got around it by unchecking and rechecking:

Project Settings -> General -> Signing -> 'Automatically manage signing'

IF this not work then try second option:

I was having this same issue. Here is what I did that solved the problem for me.

1) First I right clicked on each of the two profiles that would "grey-non-download" and moved to trash.

2) Then I deleted the developer account within Xcode.

3) I re-added the developer account, went back to details and download all.

It worked for me, hope this helps.

Be sure that you have the right signing identity for :App : General and Build SettingsAppTests : General and Build Settings

In my case for some reason the AppTests started to have the wrong settings out of nowhere.