Citrix Viewer on Mac OSX Mavericks does not work

Today I installed Citrix Receiver (aka Citrix Viewer) on my laptop and I was surprised to see that once logged in the remote host the keyboard is completely unresponsive.

Fortunately, someone on citrix blog faced the same issue.
The workaround is to press CMD-TAB keys and revert to citrix receiver.
It strangely bypass the issue.