After upgrading to Yosemite you will need to uninstall Universal Control and then reinstall version 1.7.2. Your FireStudio interface should be working after doing this.
Please follow our knowledge base guide on uninstalling and re-installing your FireStudio files/drivers: http://support.presonus.com/entries/113168-firestudio-how-do-i-uninstall-reinstall-my-firestudio-drivers-on-a-mac-computer
Applies to:
- FireStudio Project - FireStudio Mobile - FireStudio Tube - FireStudio Lightpipe Note: The Firestudio (26x26) is not supported on OS X 10.8 or higher.