Recent Custom Posts Conflict

When I attempt to use this plugin's widget I get the following error message:

Fatal error: Call to undefined function preg_filter() in /home/tad84/public_html/wp-content/plugins/recent-custom-post-type/recent-custom-post-type.php on line 191

It also freezes the widgets, so when I go back in to edit them, nothing works. I can't edit any widgets or change any of them out. I tried disabling all of my plugins and changing themes to see if there was a conflict, but it still did the same thing.