Hi,
Thank you, the FTP works now. However when I tried to access the back-end I’m getting the following error: https://i.imgur.com/OwxSF6g.png
It looks like you have some sort of a DB cache active with W3TC. I very strongly recommend turning that off, that could very well cause this issue as well. I checked WPML API, everything related on how to correctly use it, but the code the plugin uses is perfectly correct. I’m afraid there might be something else causing the conflict as well.