nothing to worry about actually, this window isnt the cause of ur dc. Its just something that happens after u alrdy dced due to isp issue or something similar. Its not a real issue to deal with cuz its not the cause of game termination.
It always happens when the game fails to close, for some reason.
Disconnecting is a reason for it to happen, as I've seen it happen once without being disconnected, but seen it happen to others when they disconnect.
But in the end, there's nothing we can do for the error to do not happen.
But since it is in the closing, it doesn't matter.