It's possible you had a bad write to your installation media or for some other reason its contents could not be read correctly. If you've tried again and are still having problems you should try re-writing the image to your media (and may be also re-download the image).
From the bug description above:
CasperMD5CheckM ismatches: ./boot/ grub/grub. cfg esult: fail
CasperMD5CheckR
It's possible you had a bad write to your installation media or for some other reason its contents could not be read correctly. If you've tried again and are still having problems you should try re-writing the image to your media (and may be also re-download the image).