Installation of Ubuntu 14.04 shows error about /boot/efi and takes forever
Solution 1:
I managed to install Ubuntu, even if not to get the process bar. However it was so quick that I didn't need it!
The error
The attempt to mount a file system with type vfat in SCSI2 (0,0,0), partition #1 (sda) at /boot/efi failed
You may resume partitioning from the partitioning menu.
led me to this post on Ubuntu Forums, where I discovered that what I needed to do was reduce the size of the EFI partition, which cannot be more than 256MB, apparently. I set mine to 200 MB, and the installation went fine afterwards.