This error occurs when the provisioning profile embedded in the .app file does not contain any devices. Can you ensure you are building with the correct profile and that it contains devices? You can do this by:

• changing the .ipa extension to .zip and upzipping the file
• in the Payload folder, right-click the .app file and select Show Package Contents
• find the embedded.mobileprovision file and open it in a text editor
• scroll down to the ProvisionedDevices key. If there are no devices in the list then you may have built the app with the incorrect profile

Ensure you are using a Ad Hoc Distribution profile when building and that Xcode is using the correct profile. Building with a Development profile or an App Store Distribution profile will not work.