Both Scheduler plugins (for WordPress and Joomla) have moved to GitHub, including the sources, the documentation, and support forum. If you need community support or would like to contribute, please visit:
Scheduler for Joomla: github.com/DHTMLX/scheduler-joomla
Scheduler for WordPress: github.com/DHTMLX/scheduler-wordpress
You can still post your questions in this forum and get help from other users.