C# Error CS0709 – ‘{1}’: cannot derive from static class ‘{0}’

C# Error

CS0709 – ‘{1}’: cannot derive from static class ‘{0}’

Reason for the Error & Solution

‘derived class’: cannot derive from static class ‘base class’

A static class cannot be instantiated or derived from. That is, a static class cannot be a base class of any other class.

Example

The following sample generates CS0709.

// CS0709.cs  
// compile with: /target:library  
public static class Base {}  
public class Derived : Base {}   // CS0709