Yes, that happens sometimes.
The best way to tackle this is to send a PM to Mark and copy the error message there.
However, it looks like this is nothing to worry about. Just try & post the loss again. There was the It's a Knockout tourney earlier today (actually, still going on, but I got knocked out in the first round ), where many dozen people may be simultaneously accessing the database, which may lead to these temporary error messages. A few minutes later, everything usually returns to normal.