Symptom:
6800IA Client fails to transfer the image from the parent.

Conditions:
Parent has extracted the image using the command:

archive tar /xtract microcode:FEX bootdisk:

And is serving as the TFTP server via the config command:

tftp-server bootdisk:<filename>

When the 6800IA attempts to transfer and boot the image, the file size may be different than what is seen on the parent, and the client may see the following error on boot:

Loading "flash:/<filename>"...flash:/<filename>: magic number mismatch: bad mzip file

And the 6800IA fails to boot successfully.