I'm getting the following error and am having difficulty getting users free access

The error I'm getting is as follows Warning: getimagesize(): http:// wrapper is disabled in the server configuration by allow_url_fopen=0 in /home/k7707128/public_html/wp-content/plugins/ultimate-branding/ultimate-branding-files/modules/login-image.php on line 246
and only the login screen opens we want our users to be able to view the site and choose to log in or not.