I wish I had seen this before following your less detailed previous advice. I partitioned my 4 GB card as FAT32. I really doubt it will make a difference, but I will redo that shortly. Kernel 4.1.21 always worked well for both versions of Ubuntu, but I suppose I could find 4.1.20 and try it. In any event, vmlinux-4.1 in Cf0: worked fine for Ubuntu LTS 12.04 both before and after the reformatting. Why not MATE? Very mysterious.jdupuis wrote: My best advice ... is what I did for myself. First. Back up all your data. ... Make sure your CF Card set up and stable. In GParted, select your CF Card, pull down Devices from menu and create Partition Table - MS-DOS. Then make your CF Card 1 entire FAT32 partition ... If yours is 4 GB or less then use FAT16. I found that Kernel 4.1.20 works very well for both Ubuntu 12.04 LTS and Mate 16.04 LTS. Stop goofing with the USB stick for Mate.
Make sure your 12.04 Install is booting and stable. Download the 16.04 image to your Downloads Folder in 12.04. Unpack with 7 zip. Do a complete erase and reformat of the Hard Drive you will use for 16.04. Delete the FAT32 Partition. GParted should show "Unallocated". Now you will use Terminal to "sudo dd" the 16.04 .img to the Hard Drive. When it is done boot with the 4.1.20 Kernel and configure 16.04 as required. Then you will be able to go into System Updater and select [Partial Upgrade]. This should bring you to the new 16.04 release. This is what I did for myself. Note that I do not have Ubuntu installed on my AOS drive. ... I hope this helps you out.
As for "messing" with the USB stick, that was Christian's advice on how to install MATE to a hard drive, and it worked beautifully. I enjoyed an updated and partially upgraded MATE 16.04 for four days. The initial upgrade (Christian's advice was "sudo update, sudo upgrade") took about an hour, so it must have been pretty close to a full one, I would guess.
By the way, although I was pretty sure what the result would be, I just booted the USB drive version of MATE. So each install of MATE, one on a rotary hard drive, one on a solid state drive, and one on a USB drive, behave exactly the same. They get past the notices "Started CUPS Scheduler" and "Starting Plymouth Boot Screen," put up an early version of said screen, and stop.
I just found out how to view the log files, and next time I am in Ubuntu 12.04 I will take a look at the ends of the most recent MATE logs, and see what happened after "Starting Plymouth Boot Screen." (Not sure which log I want to look at, but with "tail -10 /var/log/..." I can look at them all.)
But GParted not being able to do some things to my SSD drives ("Unable to satisfy all constraints on the partition") is a major part of the problem. I may just retry the drive that came (I think) with the X1000, and that I replaced with the larger SSD. I thoughtit had gone bad but maybe it will work better?
I agree with you about Christian's help. He has always been very generous with responses to my problems. You're up there too. Thanks.