leaking textures loaded from a dll

I'm creating a custom editor in a c# dll and loading textures embedded as resources in the dll. It all works fine, but when I save the scene, unity says its cleaning up leaked textures.

I'm disposing of the textures in EditorWindow.OnDisable(), and if I close the editor before saving there are no leaks. So I can't figure out how to avoid leaking textures.

Here's how I load the embedded resource:

static List<Texture2D> LoadedTextures = new List<Texture2D>();

public static Texture2D LoadDllResource(string resourceName, int width, int height)
    texture = new Texture2D(width, height, TextureFormat.ARGB32, false);

    var myAssembly = Assembly.GetExecutingAssembly();
    var myStream = myAssembly.GetManifestResourceStream("Editor.Resources." + resourceName + ".png");

    if (myStream != null)
        Debug.LogError("Missing Dll resource: " + resourceName);

    return texture;

I load textures into static variables. For example:

browserButton = new GUIContent(MyEditorUtility.LoadDllResource("browserIcon", 14, 14), "Open Browser");

Then in EditorWindow.OnDisable() I destroy the textures:

public static void DestroyLoadedTextures()
    foreach (var texture in LoadedTextures)


Again, if I close the window then save, no leaks. And if I don't destroy them, they leak. So it feels like I'm doing that part correctly.

But if I save with the editor window open, every texture I loaded from the dll leaks... is there some other window event I should be destroying loaded textures on?

Also Unity continues to report that it's cleaning up textures on every save, even though I haven't loaded any more textures (I do all loading in one place). So it seems like they're not really getting cleaned up...?

I had a similar issue to this, you need to prevent texture asset from being saved. It is also useful to hide the texture asset from user interfaces:

texture = new Texture2D(width, height, TextureFormat.ARGB32, false);
texture.hideFlags = HideFlags.HideAndDontSave;

Same thing happens with SpriteManager 2. They're a harmless artifact of the editor environment IIRC.