I really like this plug-in and use it on my own site as well as my customers' sites.
I have WP_DEBUG set to true and received this error with the most recent White Label CMS upgrade:
Notice: Undefined index: in .../.../.../.../wp-content/plugins/white-label-cms/wlcms-plugin.php on line 130
It doesn't seem to be causing any problems,that I know about, other than throwing up the error. Hope this is helpful.