Also check if your (R) is a special symbol, because if it is, remove it.
Because that's what I've read up on another thread, where someone figured that one out.
And by the way, the (R) is not required. Mine's like this;
C:\Program Files (x86)\Electronic Arts\Crytek\Crysis 2\
And now (after much hassle with the installation) the editor works just fine.