In BlackBerry® Enterprise Server versions earlier than version 5.0, the BlackBerry Policy Service queues delivery requests for IT policies and application control policies and sends them to BlackBerry devices. In BlackBerry Enterprise Server version 5.0, the BlackBerry Administration Service queues the IT policies and application control policies, and the BlackBerry Policy Service sends them to BlackBerry devices.

To avoid conflicts between the BlackBerry Policy Service and BlackBerry Administration Service in a mixed version environment, the setup application tries to turn off application polling by the BlackBerry Policy Service for each BlackBerry Enterprise Server instance in the BlackBerry Domain before it starts the upgrade process. When the setup application turns off application polling, it prevents earlier versions of the BlackBerry Policy Service from queuing delivery requests for IT policies and application control policies.

If the setup application cannot turn off application polling for all BlackBerry Enterprise Server instances (for example, a computer that hosts one of the BlackBerry Enterprise Server instances is not running), you must run the BB50UpgradePrep tool manually before you can upgrade the BlackBerry Enterprise Server.