How to choose best relationships software for your needs pps to choose from, how can you discover which one to use

Fatal error: Uncaught Error: Call to undefined function userphoto_the_author_photo() in /home/ghi1pdg9vexh/public_html/thannambikkaiweb/wp-content/themes/magazine/single.php:23 Stack trace: #0 /home/ghi1pdg9vexh/public_html/thannambikkaiweb/wp-includes/template-loader.php(98): include() #1 /home/ghi1pdg9vexh/public_html/thannambikkaiweb/wp-blog-header.php(19): require_once('/home/ghi1pdg9v...') #2 /home/ghi1pdg9vexh/public_html/thannambikkaiweb/index.php(23): require('/home/ghi1pdg9v...') #3 {main} thrown in /home/ghi1pdg9vexh/public_html/thannambikkaiweb/wp-content/themes/magazine/single.php on line 23