'reference' is not a valid named attribute argument. Named attribute arguments must be public fields which are not readonly, static or const.
An attempt was made to access a private member of an attribute class.
The following sample generates CS0617:
using System; [attributeusage(AttributeTargets.Struct|AttributeTargets.Class|AttributeTargets.Interface)] public class MyClass : Attribute { public int Name; public MyClass (int sName) {Name = sName; Bad = -1;} int Bad; // try the following line instead // public int Bad; } [MyClass(5, Bad=0)] class Class1 { // CS0617 } public class MyClass2 { public static void Main () { } }