When Moodle’s maintenance mode is enabled, only the site administrator can access the courses, and all other users will be notified that the site is in maintenance mode.
Step 1
Log into your Moodle site as an admin user, and navigate to the Maintenance settings option: Site administration > Server > Maintenance mode
Step 2
Click “Disable” from the Maintenance mode drop-down list.
Step 3
Click the “Save changes” button and your Moodle site is now out of maintenance mode, and accessible to all users.