Ran into a new quirk with imaging this summer. Most computers were imaging fine, but a few would fail while copying the boot image.

This happened even within groups of the exact same model of computers. The fix in the end was simple.

We added a DWORD registry key RamDiskTFTPBlockSize with a value of 8192 to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SMS\DP

We then restarted the Windows Deployment Service on our server and started imaging.

update: After working with this bug on and off for a couple of years we have found that the issue is almost always with the network driver. If the correct driver isn’t available to the boot image, then the boot sequence can give this error randomly.