Thank you for your post.
FileMaker Pro 13.0v9 will work under Mac OS X 10.10.3.
When you say "update fails", are you talking about FileMaker Pro update? Or, Mac OS X update?
You mention a "server". Are you running FileMaker Server? If so, what version?
If the files are local to your machine, temporarily move the database files to the desktop, remove and reinstall FileMaker Pro, as this will only update the application and not affect the files.