I'm using Ubuntu 14.04 (64) and Chromium 43.0.2357.81. But when I log in to the customer, the file launch.ica is downloaded but the Citrix app doesn't start automatically. But if I go to the drive, mark the file and open it with "Citrix Receiver Engine", everything is working. The file launch.ica has its properties set to "Always open" with "citrix Receiver Engine". When i run Firefox, same computer, OS and so on, everything is working correct. I've run the following command several times.
xdg-mime default wfica.desktop application/x-ica