Cannot Install App Over the Air

So I have an app I created for a client who has a iOS enterprise account. We have always distributed their app to their internal team with a plist and ipa on a website Over-The-Air. In the last few months (prior to iOS 8) development had settled and no changes were necessary. Unfortunately now some new work has been completed by I cannot seem to get the app to install on any device using the OTA method.

Has anyone else experienced this? How do I trouble shoot and fix this? Even iOS console gives almost no information or errors before the install fails.

Thanks in advance.