I have noticed that if I refresh on the "Sorry! There has been an error
retrieving your message from the server." page over and over after about
5-20 times it will finally show me the message. Hope that helps.
Having the same issues here. I have to mark it as unread and come back
about 30 min to an hour later and then I can get the message. Its been
doing this to me on about 20% of all our messages.