We are using xcode 6.2 beta 4 and distributing ipa with testflight without any issue.
But when distribute the ipa to an OTA link for enterprise in-house distribution, the app can't be installed. The error message captured in the console log is "attempt to install an invalid profile", "Failed to verify code signature of ...", "Signer did not match any installed provisioning profile".
The Distribution Provisioning Profiles being used is showing green in the Apple developer portal. And it's available in the Xcode. The certificate type is iOS Distribution and will expire on Jan 06, 2016. The profile has both bundle ID and cert in place.
The ipa was generated via the build, not the archive (as archive doesn't allow me to export as enterprise ipa, only ad hoc).