Unable to delete SSLs even after assigning different SSLs to the load balancers that were using the SSLs previously

Hello deliberate_kpl, sorry to hear about the issues you're having with replacing the SSL certificates for the load balancer. There could be a couple of reasons for why this is happening and I've provided some solutions below.

The first question I would ask is what you're using to manage your SSL certificates? Are you using AWS Certificate Manager? If so, here is some documentation around deleting/creating SSL certificates

IMPORTANT NOTE: You cannot delete an ACM certificate that is being used by another AWS service. To delete a certificate that is in use, you must first remove the certificate association. This is done using the console or CLI for the associated service. Deleting a certificate issued by a private certificate authority (CA) has no effect on the CA. You will continue to be charged for the CA until it is deleted. For more information, see Deleting Your Private CA in the AWS Private Certificate Authority User Guide.

To delete a certificate using the console

• Open the ACM console at https://console.aws.amazon.com/acm/

• In the list of certificates, select the check box for an ACM certificate, then choose Delete.

  Note: Depending on how you have ordered the list, a certificate you are looking for might not be immediately visible. You can click the black triangle at right to change the ordering. You can also navigate through multiple pages of certificates using the page numbers at upper-right.

To delete a certificate using the AWS CLI

• Use the delete-certificate command to delete a certificate, as shown in the following command:

$ aws acm delete-certificate --certificate-arn arn:aws:acm:region:account:certificate/certificate_ID

Hopefully this helps resolve the issue. Thank you.