C# Error Compiler error CS0629 – Conditional member ‘{0}’ cannot implement interface member ‘{1}’ in type ‘{2}’

C# Error

CS0629 – Conditional member ‘{0}’ cannot implement interface member ‘{1}’ in type ‘{2}’

Reason for the Error & Solution

Conditional member ‘member’ cannot implement interface member ‘base class member’ in type ‘Type Name’

The cannot be used on the implementation of an interface.

The following sample generates CS0629:

// CS0629.cs  
interface MyInterface  
{  
   void MyMethod();  
}  
  
public class MyClass : MyInterface  
{  
   [System.Diagnostics.Conditional("debug")]  
   public void MyMethod()    // CS0629, remove the Conditional attribute  
   {  
   }  
  
   public static void Main()  
   {  
   }  
}