Hi Hugo, we're glad the Migration module did the trick!
— PrestaShop (@PrestaShop) July 24, 2018
Concerning the 1ClickUpgrade, were you using the current version or the beta? We've done major improvements on the beta (and will continue to do so): https://t.co/KgmUz1tU7b
https://goo.gl/EO0ad1
https://goo.gl/xF8heB