[grub2] message at boot "invalid license"

Greetings !!

One of my student came with a laptop that wasn’t able to boot with grub message (I suppose because it came just after grub boot loader appeared, just before the grub menu to be displayed)
The message was saying “unable to find a boot partition – invalid license – press a key to boot”

I NEVER saw this type of error.

Any idea to know where that come from ?

Dual boot and this happened after a Windows update session?