Uncaught Error: Object of class WP_Error could not be converted to string
in /home/u170101900/domains/swimming-cool.com.ua/public_html/wp-content/themes/swimiming/single-pool.php on line 100

Call stack:

1. include()
   wp-includes/template-loader.php:106
2. require_once('/home/u170101900/dom.../template-loader.php')
   wp-blog-header.php:19
3. require('/home/u170101900/dom...l/wp-blog-header.php')
   index.php:17