did you download and install the library? If yes, have you selected a guitar via the guitar type dropdown menu in the settings tab of Guitarist?
If it's still shown as empty did you possibly select a custom folder, external custom drive or just moved the library after installation?
Anyway, you can check the instrument path in the com.Sugar-Bytes.Guitarist.plist file.
Per default the library will be installed in Aplications/Sugar Bytes/Guitarist/Library/Instrument/

Now if you want to change it to the location you want you will need a corresponding plist editor. I used Pref Setter.
So here is an example...after the installation I just moved the Guitarist Library folder from the default installation folder to my desktop.
Got to the plist (com.sugar-bytes.Guitarist.plist ) by entering ~/Library into the 'Go To Folder' menu and selected the com.Sugar-Bytes.Guitarist.plist file from the Preferences folder.
Opened the com.sugar-bytes.Guitarist.plist file with Pref Setter and adjusted the following paths to:
InstrumentsPath
/Users/"YourLogName"(here sugarbytes)/Desktop/Guitarist Library/Instrument/
LibraryPath
/Users/"YourLogName"(here sugarbytes)/Desktop/

Hope this helps.
Best,
Nadine

