We ran into some issues with signs during this last update. So, we are taking this opportunity to rework the withdrawal and depositing system. All exchanges, except for the spawn bank, have been removed throughout the world and will be replaced by a much more intuitive and accessible set of commands: /withdraw and /deposit. We expect to have the new commands online by tomorrow. Until then, the only means of withdrawing emeralds is at the main spawn bank. If you are having issues with signs near your settlement, open a ticket in game or here on the site.