Form is completely distorted upon inserting short code

I made a form and entered the shortcode and im getting a bunch of distorted text on my website that looks like this… How can i fix this?

Warning: trim() expects parameter 1 to be string, array given in /home/content/93/10805593/html/wp-content/plugins/ajax-contact/form-display.php on line 160

Warning: trim() expects parameter 1 to be string, array given in /home/content/93/10805593/html/wp-content/plugins/ajax-contact/form-display.php on line 160

Warning: trim() expects parameter 1 to be string, array given in /home/content/93/10805593/html/wp-content/plugins/ajax-contact/form-display.php on line 160

http://ww.wp.xz.cn/extend/plugins/ajax-contact/