I downloaded the Citrix receiver for Linux 13.0 (I'm running Ubuntu 13.10 64bits) from http://www.citrix.com/downloads/citrix-receiver/linux/receiver-for-linux-130.html. I unpacked it using alien, but when I try to open the receiver from the command line (as explained in the documentation) by typing /opt/Citrix/ICAClient/selfservice it tells me "Command not found". I tried to navigate to the folder from the graphical interface: I can see the file (which is of type application/x-executable) but when I double click on it nothing happens! I tried to right click and check the permissions: the executable case is ticked but it tells me that I cannot modify anything because I am not the owner... I also tried chmod from command line but nothing changes. Does anybody know why this happens??