Great. It works.

No, i didn't increase the .cache partition. But may be I deleted everything before I restored your stable backup. (Meizu Pro 5 16.04 STABLE BACKUP for restoring with TWRP). Where I get this ubuntu recovery?

I have a Meizu 5 Pro.
I installed 16.04 via restore with team win recovery project, because the update via ubports doesnt work. I wiped everything.
16.04 runs.
Now I have in updates an update called "ubuntu touch version 2".
When I install this: button "install" then button "reboot and install", the phone reboot into twrp. Is this ok?
Then I don't know, what I have I do. So I choose restart and system. Nothing changed. Everything like before.
How can I solve this? What is the right way to install this update without run into twrp?

Yes works also for me.

Hallo,
I have the same problem. My phone is also a original android and i changed to ubuntu.
The phone is in => fastboot mode (unlocked, unrooted).
When I try to flash the result is:
2017/06/17 08:24:37 Device is |turbo|
2017/06/17 08:24:37 Flashing version 1 from 15.04/stable channel and server http://system-image.ubports.com to device turbo
Can't boot recovery image

Nothing happens. What cab I do?
I made a factory reset before.