Just posting to confirm that we are aware that the login server for Singularity is down and as a consequence other services like the chat server are also not available (if you manage to login while bypassing the launcher).
Our sys admins took a look, but it seems likely, that this will need to be fixed after Easter.
After a reboot in the afternoon it seems like chat on Singularity is stable again. If you see any further weirdness: Please report it (either here or through a bug report), so that we can investigate. All other services are also back as far as I know.