1 files changed, 5 insertions, 1 deletions
diff --git a/server/src/com/vaadin/server/AbstractCommunicationManager.java b/server/src/com/vaadin/server/AbstractCommunicationManager.java
index 32800506a3..5832b144ec 100644
--- a/server/src/com/vaadin/server/AbstractCommunicationManager.java
+++ b/server/src/com/vaadin/server/AbstractCommunicationManager.java
@@ -2464,9 +2464,11 @@ public abstract class AbstractCommunicationManager implements Serializable {
     public void handleBrowserDetailsRequest(WrappedRequest request,
             WrappedResponse response, VaadinSession session) throws IOException {
 
-        assert UI.getCurrent() == null;
+        session.getLock().lock();
 
         try {
+            assert UI.getCurrent() == null;
+
             CombinedRequest combinedRequest = new CombinedRequest(request);
 
             response.setContentType("application/json; charset=UTF-8");
@@ -2495,6 +2497,8 @@ public abstract class AbstractCommunicationManager implements Serializable {
         } catch (JSONException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
+        } finally {
+            session.getLock().unlock();
         }
     }