2000z on Sunday 13th October 2019 VATSIM will be offline for 24hrs whilst Audio for VATSIM (AfV) is rolled out. Make sure your VATSIM pilot client is up to date! https://audio.vatsim.net/docs/1.0/home
VATSIM has been online again for a few hours now and all seems stable aside from a few voice disconnections. Remember to update your pilot client if you have issues connecting.