We're investigating which items/buffs/actions can lead to the "Server Zone Crash" issue. If you know what caused it for you, please let us know.
Every day, very early in the morning, our servers receive a sort of "Server Zone cleaning". This is the reason some of you may play again. However, if it's a buff or maybe a production chain, which is longer than 24 hours (so it doesn't end before the server check) you might need to wait longer before you will be able to get back in.