This has been bugging me for a long time and I can't figure out what is causing this.

I'm having an error similar to this: Null exception in _unity_self - Unity Forum

When I start Play mode while a ScriptableObject is opened in the inspector, a cryptic Null Pointer Exception is logged on the console. Like this:

ArgumentNullException: Value cannot be null.

Parameter name: \_unity\_self

UnityEditor.SerializedObject.FindProperty (System.String propertyPath) (at <4911eca47f294e18a7b3306f02701303>:0)

UnityEditor.UIElements.Bindings.SerializedObjectBindingContext.BindPropertyRelative (UnityEngine.UIElements.IBindable field, UnityEditor.SerializedProperty parentProperty) (at <ddc34215cb194bc6b42a1ae3b66800fe>:0)

UnityEditor.UIElements.Bindings.SerializedObjectBindingContext.BindTree (UnityEngine.UIElements.VisualElement element, UnityEditor.SerializedProperty parentProperty) (at <ddc34215cb194bc6b42a1ae3b66800fe>:0)

UnityEditor.UIElements.Bindings.SerializedObjectBindingContext.ContinueBinding (UnityEngine.UIElements.VisualElement element, UnityEditor.SerializedProperty parentProperty) (at <ddc34215cb194bc6b42a1ae3b66800fe>:0)

UnityEditor.UIElements.Bindings.DefaultSerializedObjectBindingImplementation BindingRequest.Bind (UnityEngine.UIElements.VisualElement element) (at <ddc34215cb194bc6b42a1ae3b66800fe>:0)

UnityEngine.UIElements.VisualTreeBindingsUpdater.Update () (at <73c3b9fa4da644c9a21a8a16d8e2909f>:0)

UnityEngine.UIElements.VisualTreeUpdater.UpdateVisualTreePhase (UnityEngine.UIElements.VisualTreeUpdatePhase phase) (at <73c3b9fa4da644c9a21a8a16d8e2909f>:0)

UnityEngine.UIElements.Panel.UpdateBindings () (at <73c3b9fa4da644c9a21a8a16d8e2909f>:0)

UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.UpdateSchedulers () (at <73c3b9fa4da644c9a21a8a16d8e2909f>:0)

UnityEngine.UIElements.UIEventRegistration.UpdateSchedulers () (at <73c3b9fa4da644c9a21a8a16d8e2909f>:0)

UnityEditor.RetainedMode.UpdateSchedulers () (at <ddc34215cb194bc6b42a1ae3b66800fe>:0)

It happens every time on specific ScriptableObjects. Here's one simple SO that causes this:

using System;
using System.Collections.Generic;
using UnityEngine;

[CreateAssetMenu(menuName = "Architecture/Localized String")]
public class LocalizedString : ScriptableObject
{
    [SerializeField] List<Localization> localizedStrings;

    public string Get(Language language)
    {
        string value = null;

        foreach (Localization loc in localizedStrings)
        {
            if (language == loc.language)
            {
                value = loc.value;
            }
        }

        if (value == null)
        {
            Debug.LogError($"{this.name} has no value for {language}; using name instead");
            return this.name;
        }

        return value;
    }

    [Serializable]
    private class Localization
    {
        public Language language;
        public string value;
    }
}

Language is just a simple enum with only English as its only possible value.

The issue happens all the time in all instances of this SO. This issue also happens to other SOs I implemented but this is the simplest one.

I'm tempted to think that this is an editor-only issue and this will not affect any build, but I just want to be sure. Any ideas about what is causing this?

PS. I'm using Version 2022.3.0f1