YouTrack is hosted at Amazon Elastic Cloud and unfortunately it’s been experiencing huge connection problems since Yesterday, which means that all YouTrack hosted instances are unavailable.
You can check AWS status here (Amazon Elastic Compute Cloud (N. Virginia)).
We apologies for inconvenience, and we are planning to move YouTrack hosted servers to another region (California) by the end of the day. So, according to our estimates, your YouTrack hosted instances should be up and running tomorrow.
This is the first time we are experiencing such a long service unavailability while using Amazon services.
JetBrains YouTrack Team