Yes, sorry about these downtimes. We try to do our best to fix these issues, and these downtimes are NOT normal.
Stevie shows this error when he is overloaded (his Server Load reaches above 200.00). Sometimes Stevie fixes it himself when the server load decreases enough for him to start up again, but sometimes he is unable to do so. Therefore, an admin has to run a command which will start a very long process which takes a few hours.