Override isvalid for sleeping craters

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

@@ -264,6 +264,11 @@ public class CraterConveyor extends Block implements Autotiler{
             ||  (tile.front() == source));
         }
 
+        @Override
+        public boolean isValid(){
+            return !dead && (added || sleeping);
+        }
+
         @Override
         public void write(Writes write){
             super.write(write);