diff --git a/libreplan-webapp/src/main/java/org/libreplan/web/orders/ManageOrderElementAdvancesController.java b/libreplan-webapp/src/main/java/org/libreplan/web/orders/ManageOrderElementAdvancesController.java
index 837baf4f8..e95883405 100644
--- a/libreplan-webapp/src/main/java/org/libreplan/web/orders/ManageOrderElementAdvancesController.java
+++ b/libreplan-webapp/src/main/java/org/libreplan/web/orders/ManageOrderElementAdvancesController.java
@@ -186,7 +186,8 @@ public class ManageOrderElementAdvancesController extends
 
     private void increaseScreenHeight() {
         if ((tabboxOrderElement != null)
-                && (!tabboxOrderElement.getHeight().equals("680px"))) {
+                && (tabboxOrderElement.getHeight() == null || !tabboxOrderElement
+                        .getHeight().equals("680px"))) {
             tabboxOrderElement.setHeight("680px");
             tabboxOrderElement.invalidate();
         }