Most issues are caused by other plugins or your theme that is interfering with the Lets-Box. Before contacting me please:
- Update the plugin to the latest version.
- Make sure you are running at least PHP version 5.3 and have the cURL extension enabled
- Try to find out what is causing the trouble by enabling your other plugins one by one and by switching to another theme.
- Check also the ‘System information’ tab on the settings page of Lets-Box.