Added a log message in core/output if the cache directory config value was not found.
diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index 9bb4a4e..fb533b0 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -185,6 +185,7 @@
 	<li>Fixed a bug in the Encryption library where an empty key was not triggering an error.</li>
 	<li>Fixed a bug in the Email library where CC and BCC recipients were not reset when using the clear() method (#109).</li>
 	<li>Fixed a bug in the URL Helper where prep_url() could cause a PHP error on PHP versions &lt; 5.1.2.</li>
+	<li>Added a log message in core/output if the cache directory config value was not found.</li>
 </ul>
 
 <h2>Version 1.7.2</h2>