Lots of warnings due to the plugin


I get a lot of errors at /wp-admin/customize.php page (what ever theme I use, even default). And these errors are shown even despite the fact I have DEBUG false in config.php

As 3 of 4 errors are due to WP - they are the consequence of the error connected with the plugin. Help me fix it pls.

WP 4.0.
P.S.- I am not authorised to give access, sorry.