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
  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;

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.

Multidimensional arrays are not supported by Unity’s serialization system. That’s why your array is not serialized and that’s why it won’t show up in the inspector. You can only serialize one-dimensional arrays