The SL-Bass, Piano, Drums, Strings are not registered plug-ins so I cannot load them into a project. They are in the C:\Program Files\Cakewalk\VstPlugins directory and that is specified in the Preferences-> File -> VST Settings.
 
I'm using Creator on a Windows Surface 3 Pro with 8 GB of memory when I travel. I'm familiar with SONAR and use Platinum in my studio.

try resetting all plugins and rescanning.  you can find that option in the Plugin Manager.