diff --git a/aspnetcore/tutorials/signalr.md b/aspnetcore/tutorials/signalr.md
index 8ef676cd93..d017204cd6 100644
--- a/aspnetcore/tutorials/signalr.md
+++ b/aspnetcore/tutorials/signalr.md
@@ -241,6 +241,10 @@ The SignalR server must be configured to pass SignalR requests to SignalR.
 
   ![SignalR sample app](signalr/_static/signalr-get-started-finished.png)
 
+> [!TIP]
+> If the app doesn't work, open your browser developer tools (F12) and go to the console. You might see errors related to your HTML and JavaScript code. For example, suppose you put *signalr.js* in a different folder than directed. In that case the reference to that file won't work and you'll see a 404 error in the console.
+> ![signalr.js not found error](signalr/_static/f12-console.png)
+
 ## Next steps
 
 In this tutorial, you learned how to:
diff --git a/aspnetcore/tutorials/signalr/_static/f12-console.png b/aspnetcore/tutorials/signalr/_static/f12-console.png
new file mode 100644
index 0000000000..273fb3a97e
Binary files /dev/null and b/aspnetcore/tutorials/signalr/_static/f12-console.png differ