I am getting this same error occurring a couple of times a minute. I can see from an internet search that websites that are publicly printing their errors are having it occur as well.
Any update on this? My error log is screen after screen of these.
PHP Warning: array_merge(): Expected parameter 1 to be an array, string given in /home/XXXXXX/public_html/wp-content/plugins/seriously-simple-podcasting/php/classes/controllers/class-frontend-controller.php on line 905