Notes

I had a strange problem where one single user couldn't connect to a Citrix Desktop. The user was able to log in to the StoreFront but after clicking on the icon for starting the Desktop, nothing happened. Sometimes, there was a spinning wheel on the icon.
After lots of trial and error (like resetting the user's profile and rebooting the StoreFront servers), the problem could be resolved by rebooting the Delivery Controllers.
That was very strange, I never had faced this before.