Fixed #7643

core/src/mindustry/core/GameState.java

@@ -59,7 +59,7 @@ public class GameState{
     }
 
     public boolean hasSpawns(){
-        return rules.waves && !(isCampaign() && rules.attackMode);
+        return rules.waves && ((rules.waveTeam.cores().size > 0 && rules.attackMode) || rules.spawns.size > 0);
     }
 
     /** Note that being in a campaign does not necessarily mean having a sector. */

core/src/mindustry/ui/dialogs/ResearchDialog.java

@@ -381,14 +381,12 @@ public class ResearchDialog extends BaseDialog{
             this.parent = parent;
             this.width = this.height = nodeSize;
             nodes.add(this);
-            if(node.children != null){
             children = new TechTreeNode[node.children.size];
             for(int i = 0; i < children.length; i++){
                 children[i] = new TechTreeNode(node.children.get(i), this);
             }
         }
     }
-    }
 
     public class View extends Group{
         public float panX = 0, panY = -200, lastZoom = -1;

core/src/mindustry/ui/layout/TreeLayout.java

@@ -11,7 +11,7 @@ public interface TreeLayout{
         public T parent;
 
         //internal stuff
-        public float mode, prelim, change, shift;
+        public float mode, prelim, change, shift, cachedWidth = -1f;
         public int number = -1, leaves;
         public TreeNode thread, ancestor;
 
@@ -21,12 +21,13 @@ public interface TreeLayout{
 
         public float calcWidth(){
             if(children == null) return width;
+            if(cachedWidth > 0) return cachedWidth;
 
             float cWidth = 0;
             for(T node : children){
                 cWidth += node.calcWidth();
             }
-            return Math.max(width, cWidth);
+            return cachedWidth = Math.max(width, cWidth);
         }
     }
 }