Eror

Hi Guys,
I’m getting this msg
Fatal error: Cannot redeclare strip_html_tags() (previously declared in /home/content/j/a/m/jameszar/html/pcluach3/wp-content/themes/delicate/functions/settings-validate.php:62) in /home/content/j/a/m/jameszar/html/pcluach3/wp-content/plugins/another-wordpress-classifieds-plugin/functions_awpcp.php on line 1909

What does it means?
Can I still use this plugin ?

Thanks!
Sarit

https://www.ads-software.com/plugins/another-wordpress-classifieds-plugin/