OMV 1.16 Kralizec - Update

Hi, I had previously OMV 1.11 Kralizec on my NAS (WD MY CLOYD).

I tried to update OMV 1.11 Kralizec to OMV 2.1 using:
1) omv-update after that
2) omv-release-upgrade
everything seems to be right.
After rebooting I can't get web gui. I have :
403 Forbidden
nginx
I can login via putty to root, I see also my data by lan.

What I should do to login by web gui.

root@MyCloud:~# cat /etc/debian_version please
8.2

I received an information that : You need to reinstall. You upgraded to Jessie. Can't fix it.

Now I started my NAS (WD MY CLOUD) with OMV 1.16 Kralizec, what I should do to properly update to OMV 2.1 SB.

Thanks for help.

I updated from Update manager and now I have 1.19 Kralizec and there are no new updates in Update manager.
What I should do to update to 2.1 Stone burner.

Thanks

I've just updated to 2.1.15.