Failed to connect to your instance

Please make sure that instance is in healthy status, passed it's checks and running. It should not be stopped/terminated while accessing it.

From the error message, it seems that instance either couldn't come up running completely or was stopped/terminated when it was accessed.

See in the following example, instance is in running state but not yet passed it's health checks, sometime it happens when we try to access recently launched instance, which hasn't completed it's health checks yet.

Instance in shut down or terminated state:

Also make sure that appropriate network settings are in place:

• Security group attached to your instance allows allows TCP port 22 for SSH to your IP atleast.
• NACL is not blocking traffic(inbound/outbound)

Also, please refer this re:Post Knowledge Center Article and this thread for additional details.

PS: If none of this helps, I'd suggest you to stop the instance and start again and make sure network settings as mentioned above are in place, this should be resolved. Lastly if you can try, then try launching new instance and see if problem persists or not. If still you see the same issue, I'd suggest you to reach out to AWS support via support case, if you have the support plan.

Hope you find this information useful.

Comment here if you have additional questions, happy to help.

Abhishek