Folder.php: Unable to find the wrapper "theme" after updating Grav

I’m not sure how to handle this error. It asks ‘did you enable it when you configured PHP?’

Is that a reference to the PHP configuration on my server or do I need to figure out what edit to make for folder.php file? I’ve made no changes to my theme, the pages, or any files. I just installed the most recent update via the admin page.

Line 220 of folder.php is highlighted:

            $directory = new \RecursiveDirectoryIterator($path, $flags);

Does this indicate I should change that line? $directory = theme rather than ‘new’?