We just recently heard back from some students about the following error message sometimes appearing:
Error: Database connection failed.
It is possible that the database is overloaded or otherwise not running properly.
The site administrator should also check that the database details have been correctly specified in config.php
I also have received this error message when trying to refresh or trying to access a link on the admin page. Any ideas what is going on? I've written Moodlerooms support, since this appear like a server issue.