The ssl cert for 'https://mint.splunk.com' was expired on 26 September 2019 and the console seems no longer work.
When will the cert be renewed?
If a Certificate has been expired then you have to renew the certificate, Splunk wont do auto-renewal.
Below is the set of document, which will help you to understand how to renew your certificates, please go through the sub links as well.
Man... It's your own company's website that expired, not mine...