Let's Encrypt ssl error: You have an invalid or missing intermediate (bundle) certifiate

You have an invalid or missing intermediate (bundle) certifiate

This error is because of the problem in the intermediate certifiate. Let's Encrypt recently updated its intermediate certificate from "Let's Encrypt Authority X3" to "R3".

https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021/

In-order to resolve the issue, downlod the latest intermediate certificate from the following url and apply the same to webserver.

https://letsencrypt.org/certificates/

That's all…