"Warning: Invalid argument…" – caused by disabling post nav?

Dear Enfold team

I just noticed that this warning “suddenly” is shown at the very bottom of all my portfolio items:

“Warning: Invalid argument supplied for foreach() in /home/u133xgf/www/wp-content/themes/enfold/functions-enfold.php on line 406”

It only shows on portfolio items, not on pages (I do not use blog posts, so I do not now the status for these).

The only thing I can think of has caused this is, that I yesterday put in this code found on your forum for hiding post navigation:

/* disable post navigation – previous and next */
add_filter(‘avia_post_nav_entries’,’avia_remove_post_nav’, 10, 1);
function avia_remove_post_nav()
{
return false;
}

Has the warning to do with this code for disabling post nav? (which does work as intended!)

And how can I keep disabling post nav but not show the warning?

Thanks in advance

PS: Log in credentials supplied in private content and my acceptance of deactivate plugins