Unable to Download Application, Application could not be installed at this time

Usually this means the app profile does not contain your device. Or there’s some confusion with another profile.

Some tips if:

A. you’re installing:
1. Delete the App
2. Delete any older profiles (Settings > General > Profiles)

B. you’re signing:
1. Delete old profiles in Organizer otherwise apps can sometimes get signed with an older profile
2. Build Clean
3. Make sure you’ve selected Release and Device when doing the Build
4. Make sure you choose the Ad Hoc Provisioning Profile

More info: