update

core/src/mindustry/content/Items.java

@@ -31,7 +31,7 @@ public class Items implements ContentList{
         }};
 
         sand = new Item("sand", Color.valueOf("f7cba4")){{
-
+            alwaysUnlocked = true;
         }};
 
         coal = new Item("coal", Color.valueOf("272727")){{