Hi Yougo,
I am trying ubports dualboot myself right now. Try this one instead of your Terminal command:
I am right now making a test myself.
I used channel:
devel-proposed - Follows Ubuntu's devel-proposed channel with testing Ubports android images
to be on more current version and now I have instead of ubuntu touch 15.04:
manta=20160126
but has bootloop 
Then I used channel:
rc-proposed - Follows Ubuntu's rc-proposed channel
And I got:
manta=20160126 with version=235
Looping again
Now for channel:
stable - Follows ubuntu's offical stable channel
And I got:
manta=20160126 with version=7
Looping again
So I am stuck with Android and Ubuntu Touch 15.04...
I used channel:
devel-proposed - Follows Ubuntu's devel-proposed channel with testing Ubports android images
to be on more current version and now I have instead of ubuntu touch 15.04:
manta=20160126
but has bootloop
Then I used channel:
rc-proposed - Follows Ubuntu's rc-proposed channel
And I got:
manta=20160126 with version=235
Looping again
Now for channel:
stable - Follows ubuntu's offical stable channel
And I got:
manta=20160126 with version=7
Looping again
So I am stuck with Android and Ubuntu Touch 15.04...
Hi Yougo,
I am trying ubports dualboot myself right now. Try this one instead of your Terminal command:
I am right now making a test myself.
Hello all,
as described here, theres is no solution to this error by now:
Nexus 10 startup
How can I get in touch? I am long-time Ubuntu desktop user ready for testing.
Thanks all!
leder