Failed to create hashes of boot files

I’m running an Nitropad X230.
I just upgraded to a bigger SSD Drive and installed Ubuntu 20.10
I proceeded to do a Factory Reset as described here:

Everything runs as described on the instructions but it never arrive to the “OEM Factory Reset Complete” window, instead I get an error message “Failed to creat hashes of boot files”

Did I miss something along the way? Any help is appreciated. Thanks!