I have Moodle 3.0.2+ (Build: 20160218) and I am having problems with the Chat when 8 or more people are online at the same time. Than all users go out and get this message:

"Error Database Conection failed. It is possible that database is overloaded or otherwise not running properly". The site administrator should also check that the database details have been correctly specified in confing.php"

I am the site administrator but I don't know how to solve this problem. I would appreciate any help. 

Thank you,

Francisco.