I have 18.04 installed on a USB drive and, now, when I try to boot from it, I get a purple blank screen followed by a black one. Nothing else happens however long I wait. Nothing material has changed on my machine other than having installed the latest kernel updates the last time I ran the OS. My PC is using an AMD RX560 card with proprietary drivers.
I do get the Grub menu from which I can make a number of selections, including Ubuntu (start normally), Advanced options, Ubuntu with Linux (latest 3 kernels and recovery modes), Memory test, and boot into Windows 10; however, nothing works.
I’ve tried recovery modes for the latest two kernels and nothing happens. I read on the web that - when using AMD proprietary drivers - your system can get problematic after an Ubuntu update, but I haven’t seen that before. And, I don’t have the menu option to use generic AMD drivers.
Can anyone help me with this? I’d rather not go through the process of reformatting the USB drive for use, since I have a lot of customizations in it.