Please note that Windows 10 18234 is now part of the live Windows 10 kernel. This is no-longer an Insider Preview issue.
Macrium Reflect has now been updated to resolve this error.
We have been made aware of a problem with the C: drive NTFS file system that affects all installations of the Windows 10 Insider Preview Build 18234.
When imaging and verifying the System volume (Drive C:), the NTFS file system verification step will fail with 'Unknown error. - Error code = 9'.
What's the problem?
NTFS contains a series of meta data file records that describe the layout and format of the file system. One of these records is named $BITMAP and contains a series of 'Bits' in a data stream that indicate which clusters in the file system are in use and which are not. Each record has multiple attributes to further describe the record and location and size of data streams. The $FILE_NAME attribute contains the allocated and actual size of the data in the stream. For the $BITMAP record the $FILE_NAME attribute contains incorrect size information. This would appear to be a problem with, or an undocumented change to, the NTFS driver shipped with the OS. This caused the file system to update the $BITMAP record incorrectly at the time of installation.
For more information on NTFS, the Master File Table (MFT) and Attributes please see here:
Why do other imaging product work correctly if this is a problem with Windows?
Unlike other imaging products Macrium Reflect uses the file system meta data described above to determine the location and size of key file system structures. There are Windows APIs that also retrieve this data but Macrium Reflect reads values directly from the file system meta data. The Windows API calls appear to be unaffected by this problem. We believe that for the $BITMAP file the size is being calculated from information in the data stream attribute. Please note that this doesn't mean that other products have a better implementation, it simply means that they are unaffected by the problem.
What's the solution?
If you are running v7.1.3317 then run the appropriate downloaded patch from any location on your PC to upgrade to v7.1.3570.