Various issues

[weswitt]

I gave Mate a try today. I can report that booting works by copying the boot files from xubuntu. I found that ethernet does not work, but wifi does. I also found that doing an upgrade fails when doing the kernel upgrade process. I get an error saying "unsupported platform".

[ChasTechProjects]

This is because the 3B+ is currently missing from the flash-kernel database, fix found at https://wiki.ubuntu.com/ARM/RaspberryPi#Update_flash-kernel_database

[weswitt]

Thanks, I found that fix last night, but haven't tried it.

Any ideas why the ethernet adapter isn't working?

[ChasTechProjects]

It's most likely an issue with the kernel that causes Ethernet to not work on the 3B+.

[rentt]

I have same issue with xubuntu. Wifi works fine, but ethernet does not work. I have tried 3B and 3B+, both them had same issue.

[Modged]

Even on normal rpi3 the issue occur I found a workaround with
ifconfig eth0 IP netmask MASK up
Still no interface in network manager but ... it works