failure code 6 usually means that the client crashed.
What game is this? If it's Team Fortress 2, the End of the Line Update had introduced some issues where specific server-set player models would crash out clients if they tried to render a ragdoll of the client who had the custom model.
There were updates on Friday last week and Monday this week dealing with this. Monday fixed most of the crashes (TF2 Prop Hunt is now playable again, for instance), but certain models will still crash players out.