what do you mean? Does the page reload? Throw an error? What happens?
Do note that not every SSL certificate can be installed on free hosting. For example, CA bundles (Like that first file) are not supported here, and only certificates of a certain length can be uploaded to the panel.
The SSL page in the IF dashboard provides trusted certificates from GoGetSSL/Google/LetsEncript for free that work with free hosting.
If you want to keep the self-signed (Which is valid for 10 years), you can use CloudFlare: