This is a known issue and it was reported under the product defect number K2-7828.
Status:
The defect K2-7828 will be fixed in a future release. When the new version is released, please refer to the “Resolved Issues” and "New Features" sections of the Product Release Notes for a complete list of change request ID's addressed in the new release.
These are available in our Documentation section of the Support Portal here .
Workaround:
After capturing the System Image (WIM), open it via "Deployments | System Images" and then click on Browse Files.
Navigate to "C:\Users\LocalAdmin_used_when_capturing_the_image\Desktop\" then delete the files kimageprep.exe and unattend.xml.
When ready, click on Commit and then Save the System Image changes..
For more information how to edit a system image, click here .