Bo,
Unfortunately, RosettaMultigraft is not available in Rosetta 3.5. If you would like to use it, at the moment, you will have to use Rosetta 2 (also know as Rosetta++). We are working on porting the old code but it has been a slow process.
Please, once you have Rosetta 2 installed and compile, let me know if you need any help using Multigraft.
Cheers,
—
Sergey Menis
Laboratory of Bill Schief