This is an installation mode that I use - This method I took from the Moto g2 Titan telegram group: https://t.me/TitanRoms
I did it from a debian-based distribution(1) Download these two files:
click-ubuntu-policy_0.1_all.deb

https://drive.google.com/file/d/1LHqKyr_pOFiRz9IhXHiyQkru0y7rrTSl/view?usp=sharing
(2) open the terminal and go to where I download the files, and install them with the following commands.
sudo apt install debsig-verify kpartx
sudo dpkg -i click-ubuntu-policy_0.1_all.deb
sudo dpkg -i ubuntu-device-flash_0.34-0ubuntu1_amd64.deb
(3) Put your moto g2 in bootloader mode (power button + volume down) and connect it to the PC
(4)Put this command in the terminal and press enter, wait for the whole process to finish.
ubuntu-device-flash --verbose --server=https://system-image.ubports.com touch --device=titan --channel=16.04/community/walid/devel --bootstrap
If everything goes well, in a few minutes you will be using UBtouch on your moto g2 titan.