It should be :
[Guid("ebc25cf6-9120-4283-b972-0e5520d0000E")]
public class ZlibException : Exception
{
public ZlibException() : base()
{
return;
}
public ZlibException(string s) : base()
{
return;
}
}
Which calls the constructor with that signature on the base implementation of this class.
But by default the .NET CLR calls the base, blank constructor for you, so you don't actually need the : base()