Hi Vinod,
Thanks for your advice. However, xdg-utils seems to be well configured, xdg-open works perfectly when launched from a terminal.
I've tried Plonqor tip, and it worked perfectly. As a matter of fact, I'm using KDE, so I've just logged in using Gnome/metacity, linked Enpass to my cloud, logged out and back to KDE, it works great now.