Fixed logic and removed the error supressing
diff --git a/system/helpers/file_helper.php b/system/helpers/file_helper.php
index f4b48b4..7a35c3f 100644
--- a/system/helpers/file_helper.php
+++ b/system/helpers/file_helper.php
@@ -352,13 +352,13 @@
 
 		if ( ! is_array($mimes))
 		{
-			if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/mimes'.EXT))
+			if (is_file(APPPATH.'config/'.ENVIRONMENT.'/mimes'.EXT))
 			{
 				include(APPPATH.'config/'.ENVIRONMENT.'/mimes'.EXT);
 			}
-			else
+			elseif (is_file(APPPATH.'config/mimes'.EXT))
 			{
-				@include(APPPATH.'config/mimes'.EXT);
+				include(APPPATH.'config/mimes'.EXT);
 			}
 
 			if ( ! is_array($mimes))