Fixed #2255

core/src/mindustry/world/blocks/distribution/Router.java

@@ -43,6 +43,11 @@ public class Router extends Block{
             }
         }
 
+        @Override
+        public int acceptStack(Item item, int amount, Teamc source){
+            return 0;
+        }
+
         @Override
         public boolean acceptItem(Building source, Item item){
             return team == source.team() && lastItem == null && items.total() == 0;