Errors after upgrade and clone not working

Hi

I have just updated to the latest version of WordPress and the latest version of the plugin.

When cloning a site, the plugin errors and as a result the site doesn’t clone properly. When I try to view the dashboard of the newly cloned site and I am directed to the original site, this ties in with the Edit Site > Settings screen only displaying Site Upload Space Quota Size whereas it would usually display the full site options.

The errors are:

Warning: preg_match() expects parameter 2 to be string, object given in /home/tutorhal/public_html/wp-includes/formatting.php on line 3435

Warning: preg_match() expects parameter 2 to be string, object given in /home/tutorhal/public_html/wp-includes/formatting.php on line 3424

Warning: preg_match() expects parameter 2 to be string, object given in /home/tutorhal/public_html/wp-includes/formatting.php on line 3435

Warning: strip_tags() expects parameter 1 to be string, object given in /home/tutorhal/public_html/wp-includes/formatting.php on line 3407

Warning: strip_tags() expects parameter 1 to be string, object given in /home/tutorhal/public_html/wp-includes/formatting.php on line 3407

Catchable fatal error: Object of class WP_Error could not be converted to string in /home/tutorhal/public_html/wp-includes/kses.php on line 1038

We were previously using WordPress 3.8 and version 2.1.4.9.1 of the plugin with which we had cloned multiple sites successfully. We have tried reverting back to that version of the plugin but we get the same error.

Please can you help?

Many thanks in advance.
Emma

https://www.ads-software.com/plugins/ns-cloner-site-copier/