My site has developed a serious problem at the back-end, and it appears that Download Monitor is the cause. As a result I deactivated it, but then it appears to be automatically re-activating itself after I install a new plugin. However when I refresh the screen, it’s still deactivated.

This is the code that keeps coming up at various points in the fault. Can anyone help?

Warning: Use of undefined constant DLM_VERSION – assumed ‘DLM_VERSION’ (this will throw an Error in a future version of PHP) in /var/sites/f/faninsights.co.uk/public_html/wp-content/plugins/dlm-email-lock/dlm-email-lock.php on line 56

Warning: Cannot modify header information – headers already sent by (output started at /var/sites/f/faninsights.co.uk/public_html/wp-content/plugins/dlm-email-lock/dlm-email-lock.php:56) in /var/sites/f/faninsights.co.uk/public_html/wp-admin/includes/template.php on line 1962