iOS distribution is such a pain in the ass! This worked for me (follow the steps in this order):
1) in the xcode organizer:
- delete all provisioning profiles
2) in the mac os x keychain:
- delete all iOS dev certificates
3) go to developer.apple.com
- log in to the member center
- revoke all certificates (edit: some redditors pointed out that this isn’t a good idea if you’re working in a bigger team. If that’s the case try just deleting expired ones.)
4) go back to the xcode organizer:
- click refresh (bottom right) under the provisioning profiles tab and
login - List item
on the popups click the positive button
5) in your xcode project go to the “build settings” tab
- under code signing pick the dev. and distr. identities
- if they are not there or not valid go to developer.apple.com and navigate to “provisioning” if they are invalid just click modify and save them again
6) go back to the xcode organizer:
- hit refresh again (bottom right)