If anyone has any hassle, the actual message you received is important.
If you get: 'server us temporarily unavailable' or 'the server is maxed out', then it is a problem which the Nine Msn people. However, it could be your server.
Sometimes, it can also be due a thing called 'packet loss' when information simply can't get through in real time. The chat room requires a clean route and some of the route links might be down.
I have found that this will happen from time to time and it's frustrating but it is always temporary, lasting at most, one or 2 daysand at best just a few minutes.
Sorry, it's out of our hands. Just keep trying, if you can.