With a BitLocker-enabled system drive on a computer that is running Windows 7 or Windows Server 2008 R2. Then, you shut down the computer. You notice the computer intermittently stops responding during shutdown. Additionally, the operating system seems to have already shut down, and then the screen turns black. However, the computer does not turn off completely. Therefore, you may notice that the computer fan and other devices are still turned on.

This problem does not occur if BitLocker is completely disabled, or if BitLocker is enabled on a data drive but disabled on the system drive.
This post explains the issue and gives you information on the hotfix, which needs to be installed to fix the same.