Compiler Error CS2019

Invalid target type for /target: must specify 'exe', 'winexe', 'library', or 'module'

The TargetType compiler option was used, but an invalid parameter was passed. To resolve this error, recompile the program using the form of the /target option that is appropriate to your output file.

The following sample generates CS2017:

// CS2019.cs  
// compile with: /target:libra  
// CS2019 expected  
class MyClass  
{  
}