Hello @dkoukoul, issues with games run with Proton are being tracked in Proton's issue tracker. Closing as a duplicate of https://github.com/ValveSoftware/Proton/issues/727 / https://github.com/ValveSoftware/Proton/issues/162.
Thanks @kisak-valve for pointing me to the right repo.
Your system information
Please describe your issue in as much detail as possible:
Installed Far Cry 3, Trying to play the game it pop ups uplay. Trying to log in it says "A ubisoft service is unavailable"
I also installed uplay on wine with wine-staging 3.14 and there it runs fine, I can log in and it installed and runs the Steam (Windows) app from which then the game is running.
Steps for reproducing this issue: