You are running Parallels, Bootcamp, VirtualBox or other similar product on your Mac so you can use RealData software under Windows.
When you launch the RealData product in Windows, the file attempts to open on Mac instead.
Solution:
See this discussion on superuser.com for more information: Stop Parallels Desktop from opening mac excel when trying to open the virtual machines
You may need to reinstall Windows Excel.
Email us for assistance.