diff --git a/engine/Sandbox.Engine/Systems/Movies/MovieResource.cs b/engine/Sandbox.Engine/Systems/Movies/MovieResource.cs
index 5be7988f..29162965 100644
--- a/engine/Sandbox.Engine/Systems/Movies/MovieResource.cs
+++ b/engine/Sandbox.Engine/Systems/Movies/MovieResource.cs
@@ -83,6 +83,8 @@ public sealed class MovieResource : GameResource, IMovieResource
 	/// <inheritdoc />
 	public void StateHasChanged( IMovieProject project )
 	{
+		ArgumentNullException.ThrowIfNull( project );
+
 		_compiled = null;
 		_editorData = null;
 		_project = project;
@@ -119,6 +121,8 @@ public sealed class EmbeddedMovieResource : IMovieResource
 	/// <inheritdoc />
 	public void StateHasChanged( IMovieProject project )
 	{
+		ArgumentNullException.ThrowIfNull( project );
+
 		_compiled = null;
 		_editorData = null;
 		_project = project;
diff --git a/game/editor/MovieMaker/Code/Session/Session.cs b/game/editor/MovieMaker/Code/Session/Session.cs
index ba75be7b..d51be4c2 100644
--- a/game/editor/MovieMaker/Code/Session/Session.cs
+++ b/game/editor/MovieMaker/Code/Session/Session.cs
@@ -281,8 +281,7 @@ public sealed partial class Session
 
 		var resourceNode = JsonSerializer.Deserialize<JsonNode>( File.ReadAllText( sourcePath ) );
 
-		return resourceNode?[nameof( IMovieResource.EditorData )];
-
+		return resource.EditorData = resourceNode?[nameof( IMovieResource.EditorData )];
 	}
 
 	internal bool SetEditMode<T>() => SetEditMode( typeof( T ) );