I am getting the below errors when creating a site

Hi, I am getting the below errors when creating a site and checking out with stripe.

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

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

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

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

Warning: strip_tags() expects parameter 1 to be string, object given in /home/instapress/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/instapress/public_html/wp-includes/kses.php on line 1038

What is causing these errors?

Regards,
Luke