Provisioning profile doesn't include the application-identifier and keychain-access-groups entitlements
This issue is related to Bug 1534145. SSL.com: P-384 curve / ecdsa-with-SHA256 certificates.
A representative from Apple estimated 558,000 certificates to become invalidated: Bug 1533655. DigiCert: Apple: Non-compliant Serial Numbers
GoDaddy, Google, Apple and Facebook (that would explain why Facebook was glitchy today) are affected.
They are working on resolving the issue right now.
That would explain our problems, folks!
Update: The issue has been resolved. Try to refresh your projects.
Workaround: change Bundle Identifier and/or Version.
I restored a profile from Time Machine when this was working and upon launch, Xcode immediately deletes and replaces it with a new one. The key difference seems to be the old profile has the get-task-allow entitlement while the new one has NO entitlements. This is definitely broken at Apple's end.
Edit: The entitlements should also include a keychain access group, but again, no entitlements at all. Should look like:
