I think you need to acquire a newer version of FileMaker or install your version 11 on an older machine. They're officially ending support in September.
"While these earlier versions may install and run on Mac OS X v10.9 Mavericks, you may encounter installation and stability issues for which there is no resolution."
Thanks, I'll look into it. I had a feeling that might be the case.
I would venture that there is, and will never be, a way to run FMS 11 on Yosemite. It took a while for FMI to update FMS 13 to run on Yosemite.