Save version chunks changed to 4-byte lengths

core/src/mindustry/io/versions/Save4.java

@@ -1,5 +1,7 @@
 package mindustry.io.versions;
 
+import mindustry.gen.*;
+
 import java.io.*;
 
 /** This version only reads entities, no entity ID mappings. */
@@ -12,7 +14,7 @@ public class Save4 extends LegacySaveVersion2{
     @Override
     public void readEntities(DataInput stream) throws IOException{
         readTeamBlocks(stream);
-        readWorldEntities(stream);
+        readWorldEntities(stream, EntityMapping.idMap);
     }
 
 }