Studio One is unable to be started by external clock. This issue must be something else.
Please use this guide to completely uninstall Universal Control: http://support.presonus.com/hc/en-us/articles/210045143-FireStudio-Family-How-do-I-Uninstall-Reinstall-my-FireStudio-drivers-on-a-Mac-computer-
Then install Universal Control 1.7.4 for OS X: http://www.presonus.com/support/downloads/firestudio-project
If still no luck, please submit a support ticket and include the following information:
Please send your computer's System Profile. You will need to have your FireStudio Project connected and powered on when you do this.
To access your MAC's System Profile:
- Apple Menu --> About this Mac... --> System Report --> File --> Save
- Save it as "your_name.spx"
- Attach the .spx file to the support ticket.