When you access the scheduled task URL directly with the browser, it works fine. When the scheduled task manager calls the page, it does not work properly.
This problem is likely caused by your page having a redirect. The scheduler does not follow HTTP redirects. When the HTTP call is made to the page on your site it must return a 200 response. If it returns a 301 or a 302 then our Scheduled Task Manager will not work correctly.
Please make sure you don't have any redirects on the page you're calling with the scheduled task manager.