出现这种错误是因为用户不在当前频道中，可以通过以下代码解决：

client.on("peer-leave", function(evt) {
  console.log("peer-leave", evt);
  // If the current user is in the channel, remove the remote stream
  var stream = evt.stream;
  if (stream) {
    var uid = stream.getId();
    if (uid !== LOCAL_USER_ID) {
      removeView(uid);
    }
  }
  if (!remoteStreamList.length) {
    $("#remote_video_div").html("");
  }
  // If the user who left the channel is not in the channel, remove the UID from remoteUsers
  var leftUid = evt.uid;
  var index = remoteUsers.indexOf(leftUid);
  if (index !== -1) {
    remoteUsers.splice(index, 1);
  }
  $("#remote_users").html(getRemoteUsersStr());
});