If you are not using the amazing FastLane build tools then it's time you did.
A sample error below
Error Domain=IDEDistributionErrorDomain Code=1
The operation couldn't be completed. (IDEDistributionErrorDomain error 1.)
Apple's WWDR certificate expired on 14/02/16 and simply replacing this certificate with the new one should solve the issue.
- Download the new certificate https://developer.apple.com/certificationauthority/AppleWWDRCA.cer
- Open keychain and remove the expired certificate from
- Add new certificate