Troubleshooting

I can connect but my chat doesn't work

Check that your system clock is set to the correct time
If it's not set correctly then you will have issues when trying to authenticate.

The mod breaks my tab bar

Make sure the file permissions for the mod folder are correct
If RimWorld can't read the mod properly then it will fail when loading up, potentially breaking the UI as seen here.

The chat panel gets really laggy when I open it

Try reconnecting to the server
This is a known issue related to how the chat messages are displayed. If there are too many, the game will lag trying to generate them all. Reconnecting will clear out a bunch of them and resolve the issue temporarily.