Just to be clear, you were able to deploy to this same computer with a version before RC10 but now you get this kernel sync panic?
Tell us a bit more about the target computer.
What manufacturer and model is it?
What firmware mode is it in Legacy (bios) or uefi?
What specifically do you have set for dhcp option 66 {next-server} and dhcp option 67 {boot-file}?
The error says that the kernel (bzImage) did not identify the virtual hard drive (init.xz). While its possible something happened to the init.xz file during the installation of RC10. I have to think something else is at fault here.