[SOLVED] Uncaught Error: Call to undefined function set_magic_quotes_runtime() when importing RSS .xml files into WordPress

If your server environment is on PHP 7.0 or above, and you use the core WordPress RSS Importer tool from your dashboard (WP-Admin -> Tools -> Import -> RSS/Run Importer ) you may run into debug output showing a line including set_magic_quotes_runtime or simply just a default generic error like this:

The site is experiencing technical difficulties. Please check your site admin email inbox for instructions.

If you check your server error logs, you'll likely see an error pertaining to set_magic_quotes_runtime like this:

PHP Fatal error: Uncaught Error: Call to undefined function set_magic_quotes_runtime()

The set_magic_quotes_runtime() function was removed from PHP 7+ (source) so you'll need to do some trickery to make it work. Thankfully, the fix should be as simple as copying the following snippet to your theme's functions.php file (anywhere after the opening <?php tag):

if (!function_exists('set_magic_quotes_runtime')) {
     function set_magic_quotes_runtime($new_setting) {
         return true;
     }
 }

One that's added, try the import again. You should be all set!