sorry, I didn't see this the previous time. You missed a doctype and root element here:

````diff
+<?xml version="1.0" encoding="UTF-8" ?>
+<srv:container xmlns="http://symfony.com/schema/dic/security"
+    xmlns:srv="http://symfony.com/schema/dic/services">
+
         <config>
             <!-- ... -->
             <encoder class="harsh"
                 algorithm="bcrypt"
                 cost="15" />
         </config>
+</srv:container>
````