Comment 27 for bug 181428

The problem occurred specifically with the server windows.ifi.uio.no belonging to the University of Oslo, and has been experienced and described by another user here:

http://dragly.org/2010/08/31/internal-licensing-error/

The solution I used was to delete, recreate and chattr +i the licence file found in ~/.rdesktop, so that it remains empty and cannot be changed.