Unable to access world 91.

Hi guys,  since the updates on other worlds have been implamented, world 91 has become unusable to me for what reason I don't know. All I get is a black screen with a green muted speaker symbol in the top left corner and nothing more, I left a message like this on the relevant forum and I had a very prompt response which was " world 91 is there as always", well it might be where that guy is but not here, I have tried repeatedly again and still a black screen, I do not want to lose my bases I have been putting a lot of work in to them. I have been playing on two worlds and never experienced any problems until now, and the other world is up and running as normal but not 91, please advise.

Regards DungButton.