@kkthnxbb Thanks for posting the video. Looks like the crash happens exactly at the point where iPXE hands over to the Linux kernel. I stepped through the video and saw it showing ok for both bzImage and init.xz. While it could be a problem with the Linux kernel as well I would expect the issue to be in iPXE.

Do I get this right, migrating the VM from ESXi 6.5.0 to ESXi 6.7.0 fixes the issue for you?

Let’s try to go back to an earlier iPXE version. Which version of FOG did you use before 1.5.9? You can download older iPXE binaries on github using this URL: https://github.com/FOGProject/fogproject/tree/1.5.8/packages/tftp (just put in whichever version you had before, 1.5.8 or 1.5.7 or …). You don’t need to download all the binaries. Just grab ipxe.efi and put that into /tftpboot/ directory on your FOG server. Then boot up the VM again.

You might want to pay attention to the iPXE version string printed when it starts just to make sure the switch of the binary actually worked.