You're allowed to authorize up to two computers and one iPad. So first:

  1. Log in at syntorial.com/account
  2. Go into the Authorizations section
  3. If all slots are filled by other devices, you'll have to de-authorize one in order to make room for the device you're trying to use.
  4. If there is an available slot, or your device is already authorized...


Download and install the latest version of Syntorial:

  1. Log in at syntorial.com/account
  2. Go into the Downloads section
  3. Download and install Syntorial
  4. If you're still getting "exceeded authorizations" error...


Reset Syntorial's authorization file on your computer:

Mac
  1. Open Finder
  2. From the "Go" menu select "Go To Folder..."
  3. Paste in "~/Library/Application Support/Syntorial"
  4. Delete the "UsersMaster.xml" file.
  5. Open Syntorial, and it should now let you authorize

PC
  1. Enable hidden files by going into your Control Panel, clicking Appearance and Personalization, and then clicking Folder Options. Click the View tab. Under Advanced settings, click Show hidden files and folders, and then click OK.
  2. Go to C:\Users[username]\AppData\Roaming\Syntorial
  3. Delete the UsersMaster.xml file.
  4. Open Syntorial, and it should now let you authorize