Add thread safety

osu.Game/OsuGame.cs

@@ -16,6 +16,7 @@ using osu.Game.Screens;
 using osu.Game.Screens.Menu;
 using OpenTK;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using osu.Framework.Input.Bindings;
 using osu.Framework.Platform;
@@ -306,9 +307,9 @@ namespace osu.Game
                     });
                 }
 
-                recentErrorCount++;
+                Interlocked.Increment(ref recentErrorCount);
 
-                Scheduler.AddDelayed(() => recentErrorCount--, debounce);
+                Scheduler.AddDelayed(() => Interlocked.Decrement(ref recentErrorCount), debounce);
             };
         }