Welll, this is getting better and better ...
I decided to give Zimbra a new chance ... I've installed a NEW FULL Ubuntu 16.04 server, configured it and installed Zimbra 8.8.6 OSE on it.
Now, lets do the migration, because since its an OSE version, no backups allowed.
Go to Zextras and get the Migration tool, and then ...
root@mail:~/zextras_migration_tool-2.4.12# ./install.sh all
Checking for existing installations ...
FOUND Zimbra 8.8.6
The ZeXtras Installer is not compatible with the Zimbra version you are running.
It's likely that:
* You are running a Zimbra version that is not YET supported by ZeXtras Migration Tool
After a new Zimbra version is released, a new ZeXtras Migration Tool version is released
as well to ensure compatibility:
please check the "News and Announcements" section of the ZeXtras Forums
) for new release information.
A complete list of Zimbra versions compatible with ZeXtras Migration Tool can be found at http://wiki.zextras.com/wiki/Compatibility_List
LOVING THIS SH....T !!!
PS - I didnt check the Zextras as recommended but since its available for almost 2 months ....