Fixed save incompatibility with missing types

core/src/mindustry/io/SaveFileReader.java

@@ -37,6 +37,8 @@ public abstract class SaveFileReader{
     "command-center", "legacy-command-center"
     );
 
+    protected int lastRegionLength;
+
     protected void region(String name, DataInput stream, CounterInputStream counter, IORunner<DataInput> cons) throws IOException{
         counter.resetCount();
         int length;
@@ -90,6 +92,7 @@ public abstract class SaveFileReader{
     /** Reads a chunk of some length. Use the runner for reading to catch more descriptive errors. */
     public int readChunk(DataInput input, boolean isShort, IORunner<DataInput> runner) throws IOException{
         int length = isShort ? input.readUnsignedShort() : input.readInt();
+        lastRegionLength = length;
         runner.accept(input);
         return length;
     }