Continuous PHP Warnings Regarding wp-includes/plugin.php

Hello WordPress Support Forum Members,

I am using WordPress 4.0.1 and Genesis theme. There are no visible signs of trouble on the front end of my website (http://www.dogfoodadvisor.com).

My site is hosted on a dedicated Linux server by Rackspace.

I was recently advised that my Apache logs have been growing at an alarming rate. They used to be about 20-30 MB in size each week before they rotated and refreshed. However, they are now reaching 100 GB in size prior to compression.

Neither I or anyone I’ve consulted with at Rackspace has an answer for what might be causing this problem.

My hosting company technician suggested that we stop logging PHP Warnings to save server resources. This has stopped the rampant growth of our logs.

He also suggested that I post a copy of the error lines here in the WP Support Forums for help or suggestions.

The Apache error logs contains hundreds of thousands of lines of php warnings that grow literally every second and always include the following same 2 lines:

PHP Warning: current() expects parameter 1 to be array, boolean given in /var/www/dogfoodadvisor.com/wp-includes/plugin.php on line 503

PHP Warning: next() expects parameter 1 to be array, boolean given in /var/www/dogfoodadvisor.com/wp-includes/plugin.php on line 507

These lines repeat over and over again around the clock.

I am completely stumped. Does anyone know what these warnings mean?

Thanks so much for any help you can provide.