Missing iOS Distribution signing identity
Solution 1:
This is the same exact error for an expired Apple cert - though I know it's not your issue, you're the #1 answer on Bing at the moment.
According to the Apple Developer Forums, the Apple Worldwide Developer Relations Intermediate Certificate Expiration expired 2/14/2016.
... This issue stems from having a copy of the expired WWDR Intermediate certificate in both your System and Login keychains. To resolve the issue, you should first download and install the new WWDR intermediate certificate (by double-clicking on the file). Next, in the Keychain Access application, select the System keychain. Make sure to select “Show Expired Certificates” in the View menu and then delete the expired version of the Apple Worldwide Developer Relations Certificate Authority Intermediate certificate (expired on February 14, 2016). Your certificates should now appear as valid in Keychain Access and be available to Xcode for submissions to the App Store.
You can get a new cert (which expires February 7, 2023). The AppleWWDRCA.cer is available on the explanation page: https://developer.apple.com/support/certificates/expiration/
BTW: it appears this new cert is installed with Xcode 7.2.1
Solution 2:
Check here: https://forums.developer.apple.com/thread/37208
Download https://developer.apple.com/certificationauthority/AppleWWDRCA.cer and double-click to install to Keychain.
Select "View" -> "Show Expired Certificates" in Keychain app.
Remove Apple Worldwide Developer Relations Certificate Authority certificates from "login" tab and "System" tab in Keychain app.
Solution 3:
Apparently, I was having the same issue as this question, the answer there solved my problem too!! Even though I had my WWDR certificate, re adding to the keychain solved my problem!
EDIT: Before doing this, here is what I did:
Exit xCode
Go to Keychain Access. Delete every certificate which has iOS in it's name. Do the same for keys as well.
Open up finder, press Go and press ALT, this will bring up the option to go to your Library. Click on that, find Mobile Devices -> Provisioning Profiles -> and delete everything from there.
Go to Member Center and revoke every certificate you have, delete all existing provisioning profiles.
Open xCode, open your project and in General select your team, under it you will get a warning and a button which says fix issue, click on that. After it is done, build your app to a real device(not simulator) and exit xCode.
Go to Member Center and go to Certificates, you will see that xCode has created a new one. Download that, and add it to your Keychain Access.
Add WWDR to Keychain Access.
Try archiving, it should work now!
Note: In Build Settings set code signing to automatic.
Solution 4:
It says very clearly. I just had to delete expired certificate as described below and download new one from this link. It is all described on this page.
What should I do if Xcode doesn’t recognize my distribution certificate? If you have a copy of the expired WWDR Intermediate certificate in both your System and Login keychains within the Keychain Access application, your certificates may appear as invalid and not be recognized by Xcode. To resolve the issue, you should first download and install the renewed certificate. Next, in the Keychain Access application, select the System keychain. Select 'Show Expired Certificates' in the View menu and then delete the expired version of the Apple Worldwide Developer Relations Certificate Authority Intermediate certificate. Your certificates should now appear as valid in Keychain Access and be available to Xcode.