Warming in a new website

Hello,

I have just bought your plugin and I have just installed the site library named "Shop" but frontpage shows this message:

"Warning
: Undefined array key "width" in
/furanet/sites/dhhair.com/web/htdocs/wp-content/themes/generatepress/inc/structure/header.php
on line
137

Warning
: Undefined array key "height" in
/furanet/sites/dhhair.com/web/htdocs/wp-con"

I tested deleting the caché and also I have desactivated the plugins. Furthermore, I tested with other site library and I dont have this warming message.

Also I have writen to the technical service of the server. Thanks