Region: EU
Browser: Google Chrome
Critical plugins: * Adblock Plus
OS: Windows
Connection type: * Router
Bug type: Substitutions
Lobby ID: 558906
Date & Time: 08 Nov 23 00:08 CET
I was playing as solly, our med ragequited, I wanted to temporarily fill the med slot while the sub was connecting, but got kicked "only lobby players can join lobby" (then I actually got the med sub slot on tf2center manually).