Fatal error: Uncaught Error: Call to undefined function username_exists() in /home/forge/squaregate.co.uk/wp-includes/version.php:100 Stack trace: #0 /home/forge/squaregate.co.uk/wp-settings.php(29): require() #1 /home/forge/squaregate.co.uk/wp-config.php(34): require_once('/home/forge/squ...') #2 /home/forge/squaregate.co.uk/wp-load.php(37): require_once('/home/forge/squ...') #3 /home/forge/squaregate.co.uk/wp-blog-header.php(14): require_once('/home/forge/squ...') #4 /home/forge/squaregate.co.uk/index.php(17): require('/home/forge/squ...') #5 {main} thrown in /home/forge/squaregate.co.uk/wp-includes/version.php on line 100