gpt + lilo + legacy bios = success
My 3 year old Lenovo T510 has legacy bios only, no UEFI.
I have read reports that stated gpt lilo incompatibility.
Using a Patriot XT Rage 32GB USB 3.0 FD (in a 2.0 socket), I performed this test.
Partitions were originally created by fdisk in the MBR scheme.
Partitions all primary linux type 83 formatted ext4
1 10GB sandbox
2 10GB data
3 5GB Slackware64 v14.1
With gdisk, I changed partition 1 type 8300 to ef02 and wrote a new GPT on the drive. There were no errors shown. (I did NOT set the bootable flag.)
Mounted the FD and executed lilo -r /mnt/sdb3; again, no errors.
Unmounted all and rebooted into the FD (not my SSD). In a few seconds there was a perfectly functioning Slackware system; no errors whatsoever.