Thank you for posting and sorry to see that you are having trouble running TheBrain 9. Is anything showing up in your Output.log file?
This file is typically located in:
Macintosh HD/Users/[user name]/.TheBrain/v9/Logs
The .TheBrain folder is not normally visible on Mac OS. To get to the log folder: Help -> Open Log Directory
Or open Finder: Go -> Go to Folder
and type "~/.TheBrain" (without quotes). Then go to: v9 -> Logs
Also, I'll Direct Message you a link to download the latest build to see if this resolves the issue for you.