diff --git a/.gitignore b/.gitignore
index 7997bff4..a7ee0fb7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,5 @@ npm-debug.log
 
 # Ignore webpack generated files
 dist/
+
+.DS_Store
diff --git a/404.html b/404.html
new file mode 100644
index 00000000..23b32693
--- /dev/null
+++ b/404.html
@@ -0,0 +1,6 @@
+No content was found at this location.<br/>
+If you are trying a sandbox sample, you need to use the sandbox server.<br/>
+<br/>
+npm run start-sandbox<br/>
+<br/>
+See the readme for more information.