Some Mac users who had previously used a trial version of Ableton Live and since purchased a full version may be unable to Authorize or use The Bridge.
NOTE: Make sure you are launching the full version of Ableton Live and not the trial version.
You will need to delete the Scratch Live 'plist' file by following these steps:
1. Close all applications.
2. Navigate to the following folder:
Macintosh HD:/users/[your username]/library/preferences/
NOTE: Do NOT use Finder's search function to find these files. The search index of OS X does not keep track of any files which are located inside the library folders, so you won't find them. Please navigate to these files manually by following the exact paths.
3. Delete the file "com.serato.scratchlive.plist".
4. Relaunch both Ableton Live and Scratch Live and you should be good to go.
If you are still not able to authorize The Bridge please start a new help request here: www.serato.com