dnu restore problem (System.UnauthorizedAccessException)

Does anyone have an idea why "dnu restore" would throw a System.UnauthorizedaccessException?

I am upgrading from beta5 to beta8 on a Win 8.1 machine.  Running in Administrator shell.

Microsoft .NET Development Utility Clr-x86-1.0.0-beta8-15858

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System.UnauthorizedAccessException: Access to the path 'C:\Windows\system32\LogFiles\WMI\RtBackup' is denied.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileSystemEnumerableIterator`1.AddSearchableDirsToStack(SearchData localSearchData)
   at System.IO.FileSystemEnumerableIterator`1.MoveNext()
   at System.Collections.Generic.List`1.InsertRange(Int32 index, IEnumerable`1 collection)
   at Microsoft.Dnx.Tooling.RestoreCommand.<Execute>d__68.MoveNext()
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Restore failed
Access to the path 'C:\Windows\system32\LogFiles\WMI\RtBackup' is denied.

This may be the wrong place to ask, but any idea what the C:\Windows\system32\LogFiles\WMI\RtBackup folder is for and why it needs to access it?