Call a Method which has params using Reflection

I am trying to call a method that has Params using reflection. It is returning System.Reflection.TargetParameterCountException

This is happening only to the methods which have params keyword in method parameters

Public static dynamic Function(JObject data, string PathFunction) {            

        string MethodName = "MergeFields";
        string FunctionsNamespace ="Test.Functions";

        Object[] parameterArray = {"274-84-3068","5","1","Hugenberg","4","0"}

        // Call Static class functions 
        Type type = Type.GetType(FunctionsNamespace);            
        Object obj = Activator.CreateInstance(type);            
        MethodInfo methodInfo = type.GetMethod(MethodName);            
        object st =  methodInfo.Invoke(obj, parameterArray);
        return st;

    }



     public static string MergeFields(params string[] data)
    {
        StringBuilder sb = new StringBuilder();
       // code to be processed
        return sb.ToString();
    }