Amid the rollout of September's Updates, Microsoft is warning customers about a condition where security updates can't be installed on Windows Server 2012 if BitLocker is not available.
To fix this, and to ensure you can apply future security updates, Microsoft has now provided a hotfix. The problem has been identified in action for Windows Server 2012, but Microsoft suggests that the problems also exists for Windows 8 and Windows RT. Note that the issue does not affect Windows 8.1 or later, or Windows Server 2012 R2. So, only those who haven't upgraded from the original releases will be affected.
The hotfix is available from Windows Update or from the following locations: