Factorio Forums

When someone connects to a server the chat isn't working.
All messages that are send in that time will only be delivered once the person is finished with connecting.

If you mean messages between the person who is connecting and others, than yes, it is not a bug.

No I mean between all the people that are already on the server and have to wait and cant even chat with each other.

If you mean when the map is being saved, than yes. But that is how the game was designed. The map saving should take couple of seconds max.