When using the Cristie Linux XBMR ISO to run a recovery on a uEFI system, the ISO will fail to boot if Secure Boot is enabled. (Cristie Windows DR ISOs supports secure boot).
e.g. in vSpere under VM options / Boot options for the VM, untick Secure boot
On a physcial system the location of the setting is dependent on the system. Please check with your team for a specific model.