So, yesterday I was playing with my friend on my minecraft (survival)server. I wanted to ask something, so I typed a message in the chat. When I het enter, I just got kicked, with the message "received chat packet with missing or invalid signature". Also, if I joined the server a message saying

"Chat messages can't be verified

Messages sent on this server may be modified and might not reflect the original message"

I'm not entirely sure if this is a bug, but it could be, since th day before this happened there was nothing wrong nor different in the server (except this bug).