Hi, I know this is an older thread but I am having the same issue as the original poster.
I am using Inventor 2013 Design Suite Premium on a Windows 7 64 bit professional O.S.
Inventor crashed on me and when I opened it up and went to change some dimensions on a sketch, the leader lines were there with no arrows and no dimension numbers. I was able to edit the dimension though. Figuring I might of changed the dimension style somehow I went to go into the Application options and got the same message as the OP.