Since the guild hall update, myself and a few other players have been experiencing both or the latter:
- Spiral Knights terminating itself instantly
I personally noticed this happening occasionally in months prior to the update, but it is particularly frequent now. It commonly occurs when alt-tabbing, particularly during loading periods, and may sometimes happen without any suggestive triggers.
- The game, particularly after a crash of the above, will cease to load properly upon logging in, never reaching the character select or loading the level
This may also happen after force-closing the game via Task Manager.
It seems the only way to get back on is to wait for your character to be registered as disconnected, so it may time out and auto-disconnect from the server. Until then, Spiral Knights will effectively hang at the logon screen after logging in, yet will continue to load RAM until it caps out at varying thresholds (will load over 1GB until it levels out on my system).
I have not asked around to get an idea of how common the issue has been (though it also has to be considered that not all players play the game in similar ways), but these are identical experiences between myself and a few others.