The dllimport attribute must be specified on a method marked static and extern
The dllimport attribute was used on a method that did not have the correct access keywords.
The following sample generates CS0601:
using System; public class C { [dllimport("KERNEL32.DLL")] extern int GetCurDirectory(int bufSize, StringBuilder buf); // CS0601 // try the following line instead // static extern int GetCurDirectory(int bufSize, StringBuilder buf); } public class MainClass { public static void Main () { } }