Kali installation stuck at Install the GRUB boot loader
Solution 1:
Try to do the installation without an internet connection.
You can skip some steps that require internet by hitting the esc key and manually select the next step.
When everything is installed you only need to set the repository URL in the sources.list manually.
cd /etc/apt/source.list
gedit sources.list
add the line at the top:
deb http://http.kali.org/kali kali-rolling main contrib non-free
and run the apt-get update, you know how it works.