My EditorWindow won't display properly, even when commented out.

Hey,

I recently made an editor script and it was working fine. I added a line of code that didn't work, so I removed it. Now, every time I open the editor window, it doesn't appear despite all of my Debug.Log()'s going off, no errors showing up in the console, and none of my try's being caught.

This small editor-window-esque bit shows up sometimes in the top left: https://gyazo.com/5cebcc959a395aa36c7f621766144db4

My code, despite it being sloppy right now and not useful:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEditor;
 using System.Linq;
 
 public class ItemEditor : EditorWindow {
     [MenuItem("Durian Utilities/Item Editor")]
 
 
     public static void ShowWindow()
     {
         GetWindow(typeof(ItemEditor));
     }
     private void OnFocus() 
     {
         //initItems();
     }
     
     List<InventoryItem> items = new List<InventoryItem>();
    
     private void initItems ()
     {
         Debug.Log("Got this far");
         items = Resources.LoadAll<InventoryItem>("Items").ToList();
         int id = 0;
         foreach(InventoryItem item in items)
         {
             item.id = id;
             id++;
         }
         Debug.Log("And this far, too");
         Focus();
     }
 
     private void OnGUI()
     {
         Debug.Log("Made it to ONGUI");
         position = new Rect(new Vector2(-1920,0), new Vector2(500, 500));
         GUILayout.Label("Item Editor © Vextin 2027", EditorStyles.centeredGreyMiniLabel);
          //a bunch of stuff down here is commented out
          }
     }
 }

I guarantee that this isn't a script issue, but may as well give details.

I'm using Unity 5.6.0f3

So, does anyone know of a reason for this to not be working?

EDIT: I just made a separate script and it doesn't display its window either.

Relaunched Unity and got the errors

Removed empty DockArea while reading window layout: window #5, instanceID=11774 UnityEditor.WindowLayout:LoadWindowLayout(String, Boolean)

and

Error while reading window layout: window #1 is null UnityEditor.WindowLayout:LoadWindowLayout(String, Boolean)

None of my custom editors are loading, still.