"Access Denied" error when you run mpclaim.exe command to retrieve MPIO configuration reports in Windows Server 2012 R2

Applies to: Windows Server 2012 R2 DatacenterWindows Server 2012 R2 StandardWindows Server 2012 R2 Essentials


When the Encrypting File System (EFS) feature is disabled, such as by Group Policy, retrieving the MPIO configuration by using the mpclaim command together with the -v option causes an "Access Denied" error and doesn’t show the configuration. 

Note MPIO represents Microsoft Multipath I/O.


This issue occurs because mpclaim always tries to write the configuration to an encrypted file.


To fix this issue, install June 2016 update rollup for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2.

Note After you install this update, mpclaim -v config.txt will continue to try to write to an encrypted file and won't work correctly when EFS is disabled.  You should use the -n flag, mpclaim -v config.txt -n, which will write to a file that's not encrypted and succeed whether the EFS feature is disabled or not.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


Learn about the terminology that Microsoft uses to describe software updates.