I have a problem to add https to my EC2 instance and maybe you guys can have the answer to make it work.
I have a load balancer that is forwarding the connection to
Do you have an HTTPS listener on your EC2 instance? If not, your instance port should be 80 for both load balancer listeners.
Elastic Load Balancer can not forward your HTTPS requests to the server. This is why SSL is there : to prevent a man in the middle attack (amongst others)
The way you can get this working is the following :
configure your web servers Security Group to only accept traffic from the load balancer.
(optional) be sure your Web Servers are running in a private subnet, i.e. with only private IP addressed and no route to the Internet Gateway
If you really need to have an end-to-end SSL tunnel between your client and you backend servers (for example, to perform client side SSL authentication), then you'll have to configure your load balancer in TCP mode, not in HTTP mode (see Support for two-way TLS/HTTPS with ELB for more details)
More details :