diff --git a/core/src/io/anuke/mindustry/maps/Maps.java b/core/src/io/anuke/mindustry/maps/Maps.java
index 81df8640c2..932045d016 100644
--- a/core/src/io/anuke/mindustry/maps/Maps.java
+++ b/core/src/io/anuke/mindustry/maps/Maps.java
@@ -60,7 +60,9 @@ public class Maps{
             maps.sort();
         });
 
-        ((CustomLoader)Core.assets.getLoader(Content.class)).loaded = this::createAllPreviews;
+        if(Core.assets != null){
+            ((CustomLoader)Core.assets.getLoader(Content.class)).loaded = this::createAllPreviews;
+        }
     }
 
     /**