quick fox for licence problems with mac osx – i just remove the licence and test from then on…
from a terminal :
rm -rf /Users/Shared/Microsoft/RDC\ Crucial\ Server\ Information/RDCGlobal\ Data
sudo rm -rf /Users/Shared/Microsoft/RDC\ Crucial\ Server\ Information/*
try again – no need to change the machine name like the dreaded windows 😉