LogIn to system via Admin and go to page: /admin/config
Enable debug mode. Repeat action, that not work correct.
Go to Logs page /admin/config/error_logs and view error.
Send log to our mail: firstname.lastname@example.org
First of all, make a sure that your notification system has been correct configured. Go to system, by admin priviliges and go to page: /admin/config/notify
Select the required service, complete the required fields, save the settings and test. If you see errors - You can see what is wrong. If you do it hard - write log errors to us on mail: email@example.com, so that we can help you to understand them.