fixed #9017

core/src/mindustry/world/blocks/power/BeamNode.java

@@ -190,7 +190,7 @@ public class BeamNode extends PowerBlock{
 
                 if(next != prev){
                     //unlinked, disconnect and reflow
-                    if(prev != null){
+                    if(prev != null && prev.isAdded()){
                         prev.power.links.removeValue(pos());
                         power.links.removeValue(prev.pos());
 

core/src/mindustry/world/blocks/power/PowerGraph.java

@@ -377,6 +377,10 @@ public class PowerGraph{
         if(entity != null) entity.remove();
     }
 
+    public int getId(){
+        return graphID;
+    }
+
     @Deprecated
     private boolean otherConsumersAreValid(Building build, Consume consumePower){
         if(!build.enabled) return false;