This is a comment on Upgrade to 5.5, posted by Mangalor at 26.04.2018 15:03

View source for Impossible to change properties of the user in Admin panel

One more bug: it is impossible to change properties of the user in Admin panel. It occurs because integer parameter user_id is quoted before transformation to int. It can be fixed as: %%--- user_users.php.orig
+++ user_users.php
@@ -218 +218 @@
-				"AND user_id <> " . (int) $engine->db->q($_POST['user_id']) . " " .
+				"AND user_id <> " . (int) $_POST['user_id'] . " " .%%