This is unfortunately a bug with the MegaHost theme - thanks to one of our clients who took the time to find the cause of this issue, we can give you the following solution to stop this from happening:

The problem is caused by the header image for the client area.
Inside the megahost/inc/extra-codes/header-admin.php file, the line with: style="background-image: url('<?php echo $maison_img;?>');" causes the problem.

You will need to add an image to the header of the client area page to resolve the problem.