Merge pull request #12804 from peppy/fix-autoplay-load-fail-nullref

Fix a potential nullref when starting `Player` with autoplay disabled and beatmap fails to load

osu.Game/Screens/Play/Player.cs

@@ -154,6 +154,9 @@ namespace osu.Game.Screens.Play
         {
             base.LoadComplete();
 
+            if (!LoadedBeatmapSuccessfully)
+                return;
+
             // replays should never be recorded or played back when autoplay is enabled
             if (!Mods.Value.Any(m => m is ModAutoplay))
                 PrepareReplay();