This has happened for both my brother and I.

I join the game and attempt to talk to anyone else in the server and when i send the message, i get a notification that I "cannot send chat message"

I also cannot send any commands, so I cannot warp home or otherwise change world without the use of a stargate.

This applies to any and all messages and commands for me. I noticed it started about two or three days ago.

I hope this helps!
-Batman5401

I personally don't have any problems with that and most other players it seems don't have any problems with that. Are you by chance using a modded client?

I am not, actually not even running custom textures at the moment. I'll check again once the server goes back up. This could have been problems with my internet.

Actually, because our router was down last week, we switched to an exclusively wired connection. Do you have any knowledge of this affecting anything? My only thought would be the server not fully identifying my ip address. Long shot, i know, but that's the only thing that has changed in the past week or so.

Just got back on. Still in place, unable to send messages

I can't see "anything" in the server configs that would block your ability for chat messages, and I haven't heard of anyone else having that problem.

I don't see anything in terms of blocked messages in the server console when you were on earlier.

One possibility that could cause it is that the chat packets from your client are getting blocked along the way(some kind of packet/protocol blocking some isp providers use to block things like bittorrent.).

Another is that the server might see you as being dead when your not(never personally seen this happen myself, but it might be possible.). You could try to kill your self on the server to see if that does anything.

Okay, ill try and see about these, could you change my game mode then? I'm in creative and cannot kill myself.

took creative off.