Every so often (normally after leaving a server or attempting to and failing to join one) the "servers.dat" file randomly seems to replace itself with a "servers.dat_tmp". I can never know when this will happen, I am just really annoyed when it does. To fix this problem, all I must do is rename "servers.dat_tmp" to "servers.dat" and refresh the server list. I have attached my launcher's Development Console output after it happened. It happened around 3:34 PM (15:34 in the console).