In the PluginAPI.h file (no version id in the file) the plgName function is declared as returning the type LPCTSTR (long pointer to const T string). As a convenience for porting, the placeholder "T" changes for ANSI, Multibyte, and Unicode builds according to preprocessor definitions.
So, the recommended (and common) way to code plgName is this:
PLUGIN_API LPCTSTR plgName( void )
// called by gui thread - sim thread not running
return TEXT("MySbPlugin"); // app.Name();
Unfortunately, that results in the plugin name appearing as the single character "M". I assume this is