statsgraph fix

src/ui/controller/SaveController.java

@@ -429,7 +429,9 @@ public class SaveController {
 			JsonObject dataSet = new JsonObject();
 			for (int i = 0; i < model.getGraphTable().get(k).getStatGraph().getDataSets().size(); i++) {
 				TrackedDataSet set = model.getGraphTable().get(k).getStatGraph().getDataSets().get(i);
-				dataSet.add("ID", new JsonPrimitive(set.getCpsObject().getId()));
+				AbstractCpsObject cps = set.getCpsObject();
+				
+				dataSet.add("ID", (cps == null ? null : new JsonPrimitive(cps.getId())));
 				dataSet.add("COLOR", model.getGson().toJsonTree(set.getColor(), Color.class));
 				dataSet.add("PROPERTY", new JsonPrimitive(set.getProperty()));
 				temp.add("" + i, model.getGson().toJsonTree(dataSet));

src/ui/view/GUI.java

@@ -71,8 +71,10 @@ import javax.swing.tree.TreeCellRenderer;
 
 import org.apache.commons.compress.archivers.ArchiveException;
 
+import com.google.gson.JsonNull;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParseException;
+import com.google.gson.JsonPrimitive;
 
 import classes.AbstractCpsObject;
 import classes.Category;
@@ -2366,7 +2368,7 @@ public class GUI<E> implements CategoryListener {
 		for (String k : keys) {
 			if (!k.equals("KEY")) {
 				obj = json.get(k).getAsJsonObject();
-				cps = controller.searchTracked(obj.get("ID").getAsInt());
+				cps = (obj.get("ID") == JsonNull.INSTANCE ? null : controller.searchTracked(obj.get("ID").getAsInt()));
 				prop = obj.get("PROPERTY").getAsInt();
 				color = model.getGson().fromJson(obj.get("COLOR"), Color.class);
 				stat.addObject(new TrackedDataSet(cps, prop, color));