Hello.

Is it possible to connect to EC2 using SSH?
If you can connect via SSH, try connecting to EC2 and check if the processes necessary to run applications such as the web server are running in EC2.

Nope, couldn't connect using SSH

After upgrading your instance from t2.nano to t2.medium and encountering connection issues with your app, there are a few things you might want to check. Firstly, ensure the instance is running and passing all status checks in the AWS Management Console. Verify that the security group rules are correctly configured to allow inbound traffic on the necessary ports, and check the Network ACLs for any restrictions.

Connecting to your instance via SSH can help you determine if the application is running properly. Look through system and application logs for any errors that could indicate why the app isn’t accessible. Also, confirm that any Elastic IP associated with your instance is still correctly assigned, as upgrades can sometimes affect these settings.

Make sure your application is binding to the correct IP address and port, and check firewall settings on the instance itself. If your application relies on instance metadata or IAM roles, double-check that these are still configured correctly post-upgrade. Sometimes, simply rebooting the instance can resolve transient issues.

If you’re still having trouble, providing more details about the application and any error messages will help in diagnosing the issue more accurately.

Thank you Giovanni.... 1st restart I have the same address, 2nd restart i got a new one.... I can connect to the instance now but the Webapp has an out-of-date SSL cert so first I think that I need to change the elastic IP address to a fixed one, do you know if this is possible? BIG thanks for responding to my question as sometimes forums are a little quiet - much appreciated :-)

EC2 supports static IP. Please see this link: https://repost.aws/knowledge-center/ec2-associate-static-public-ip