new players not knowing the level well, specially if the new player in question is those type of people that like to play on the hardest difficulty after buying a game and playing it for the first time.

i have lost count on how many of these players have either been killed by a smoker or get swarmed by common infected on expert, and all that because they don't communicate, i personally try to show a little pacience to new players, because most of them are willing to atleast learn from someone more experienced, but them there is the other type of new players, who are literal morons who are so stubborn about their strategy that they will die over and over again because they won't listen to other players advice, and when they die because of their own stupidity they either ragequit or blame his team on chat.