To use LWC use the commands /lock and /unlock To talk in the chat channels use /ch g for global /ch auc for auction /ch tr for trade and /ch l for local
Hello isxana, The issues that you are having are two fold, the reason you are unable to lock anything is most likely due to the fact you are trying to lock something in a world that does not allow lwcs, which I think is the mining world. I would highly recommend buying a plot in a main world town so you are able to lock and secure your things. I would ask to join on in trade chat "/ch tr" in-game. Now for the issue of not being able to chat, that is most likely due to having chat disabled in the Minecraft settings, as mutes of any kind are not used on EcoCityCraft. To enable chat, go to "Options> Muiltiplayer Settings" and click the button on the top left until it reads "Chat: Shown" If you have an further issues, feel free to reply to this thread.
