diff --git a/back/src/org/kar/karideo/api/DataResource.java b/back/src/org/kar/karideo/api/DataResource.java
index 5b6a24f..20d020c 100644
--- a/back/src/org/kar/karideo/api/DataResource.java
+++ b/back/src/org/kar/karideo/api/DataResource.java
@@ -356,7 +356,7 @@ public class DataResource {
     public Response retriveDataId(@Context SecurityContext sc, @HeaderParam("Range") String range, @PathParam("id") Long id) throws Exception {
     	GenericContext gc = (GenericContext) sc.getUserPrincipal();
         System.out.println("===================================================");
-        System.out.println("== DATA retriveDataId ? " + gc.user);
+        System.out.println("== DATA retriveDataId ? " + (gc==null?"null":gc.user));
         System.out.println("===================================================");
         DataSmall value = getSmall(id);
         if (value == null) {
@@ -375,7 +375,7 @@ public class DataResource {
     public Response retriveDataThumbnailId(@Context SecurityContext sc, @HeaderParam("Range") String range, @PathParam("id") Long id) throws Exception {
         GenericContext gc = (GenericContext) sc.getUserPrincipal();
         System.out.println("===================================================");
-        System.out.println("== DATA retriveDataThumbnailId ? " + gc.user);
+        System.out.println("== DATA retriveDataThumbnailId ? " + (gc==null?"null":gc.user));
         System.out.println("===================================================");
         DataSmall value = getSmall(id);
         if (value == null) {
@@ -422,7 +422,7 @@ public class DataResource {
     public Response retriveDataFull(@Context SecurityContext sc, @HeaderParam("Range") String range, @PathParam("id") Long id, @PathParam("name") String name) throws Exception {
         GenericContext gc = (GenericContext) sc.getUserPrincipal();
         System.out.println("===================================================");
-        System.out.println("== DATA retriveDataFull ? " + gc.user);
+        System.out.println("== DATA retriveDataFull ? " + (gc==null?"null":gc.user));
         System.out.println("===================================================");
         DataSmall value = getSmall(id);
         if (value == null) {