Warnings on our blog and home page

Please help!

This “Warning” message appears across our blog (https://foresightdesign.org/blog/):
Warning: Missing argument 2 for wpdb::prepare(), called in /home/content/f/o/r/foredes/html/blog/wp-content/plugins/category-icons/category_icons.php on line 1047 and defined in /home/content/f/o/r/foredes/html/blog/wp-includes/wp-db.php on line 990

Also, info from the blog shows up on our website home page (https://foresightdesign.org/), but this “Warning” are showing there too:
Warning: Invalid argument supplied for foreach() in /home/content/f/o/r/foredes/html/inc/feedreader.php on line 16

Can anyone please shed some light on what’s happening here?