Hello 
Sometimes, when a component or plugin fails, the site may get stuck on the splash screen. Furthermore, the administrator may not detect the problem immediately or if they do than it could require more time to fix. A message displayed to visitors in such cases would help them either report the error or contact the site administrator through other means.
Actually this message can display always on splash screen. e.g. same way like on Gmail.
This message could include a link for those forums which has a main site or a contact email. It would be customized in site settings or the display of the message could be turned off entirely.
Mockup
