diff --git a/app/ecs/ecs.js b/app/ecs/ecs.js
index 25480a4..e8e08a0 100644
--- a/app/ecs/ecs.js
+++ b/app/ecs/ecs.js
@@ -122,7 +122,10 @@ export default class Ecs {
     const componentNames = Object.keys(ecs.Components);
     const {entities, systems} = decoder.decode(view.buffer);
     for (const system of systems) {
-      ecs.system(system).active = true;
+      const System = ecs.system(system);
+      if (System) {
+        System.active = true;
+      }
     }
     const specifics = [];
     let max = 1;
diff --git a/app/engine/engine.js b/app/engine/engine.js
index b4c2d60..d717647 100644
--- a/app/engine/engine.js
+++ b/app/engine/engine.js
@@ -92,7 +92,10 @@ export default class Engine {
       'RunAnimations',
     ];
     defaultSystems.forEach((defaultSystem) => {
-      ecs.system(defaultSystem).active = true;
+      const System = ecs.system(defaultSystem);
+      if (System) {
+        System.active = true;
+      }
     });
     const view = Ecs.serialize(ecs);
     await this.server.writeData(