Fixed #5448

core/src/mindustry/game/Gamemode.java

@@ -38,7 +38,6 @@ public enum Gamemode{
         rules.infiniteResources = true;
         rules.editor = true;
         rules.waves = false;
-        rules.enemyCoreBuildRadius = 0f;
         rules.waveTimer = false;
     });
 

core/src/mindustry/world/Build.java

@@ -134,6 +134,7 @@ public class Build{
             return false;
         }
 
+        if(!state.rules.editor){
             //find closest core, if it doesn't match the team, placing is not legal
             if(state.rules.polygonCoreProtection){
                 float mindst = Float.MAX_VALUE;
@@ -153,6 +154,7 @@ public class Build{
             }else if(state.teams.eachEnemyCore(team, core -> Mathf.dst(x * tilesize + type.offset, y * tilesize + type.offset, core.x, core.y) < state.rules.enemyCoreBuildRadius + type.size * tilesize / 2f)){
                 return false;
             }
+        }
 
         Tile tile = world.tile(x, y);