c# class array not showing up in inspector

This might seem like a stupid question, but I can't figure out why it doesn't work.

I have a c# class not inheriting from MonoBehaviour and marked as serializable. Then I have another (normal MonoBehaviour) class which has a two-dimensional array of that first class. I tried everything but the two-dimensional class array won't show up in the Inspector.

The code goes about as follows: //file name Master.cs using UnityEngine; using System.Collections;

 public class Master : MonoBehaviour {
   //header doesn't even show up, only if i put another variable after it
   [Header("Stuff")]
   someClass[,] xyz = new someClass[1,1];
   //someClass[,] xyz; -> didn't work either
 
   [Header("Other Stuff")]
   public int otherVar = 0; //both work
   public bool bar = false;
 }
 
 [System.Serializable]
 public class someClass {
   public int var1 = 23;
   public string var2 = "foo";
 }

I tried everything and looked for solutions, but nothing helped. All the code in the main class works and I'm sure all the someClass handling works (I get no errors), but I need the class array to show up.