Not able to access Dremio on AWS

Suddenly i am not able to access drmio on my aws machine. Anybody aware of any kind of possibel errors. The instances are up an running,

Are Dremio nodes running on those instances?

What do the Dremio logs report? These are usually found in /var/log/dremio/. Check server.log and server.out on the coordinator for information about what might be happening.

Hello Ben,
I rebooted mymachine and i got it back but now i am having an error for authentication whenevr i am trying to login. Do you have any idea why i am gettign that . I didnt changed my password.