Every blog on Typepad has an SSL certificate included upon setup, even if you are utilizing Domain Mapping, you do not need to buy an additional SSL certificate through a third-party in order for your blog to load securely.
However, just because the certificate is included, does not mean that all of your content is loading securely. Visitors may still encounter a security warning when visiting your blog. There is no need to panic. There are a number of reasons why your blog may still be loading with a broken padlock showing in your browser. The culprit is usually just as simple as updating the prefix of your URL from http to https.
Third Party Widgets
When was the last time you checked your sidebar for outdated or broken links and images? Links to a non-secure third-party can trigger a security warning. If you go to that third-party's website, you may find an updated code to add to your blog which will load securely.
Update Image URL
Most Typepad URLs automatically redirect from the http version to the https equivalent link. Image URLs that get uploaded directly into a blog post, page, or sidebar may not always work and the URL's need to manually be updated. You did not lose your image - simply change the the image link from http to https.
Uploaded Files Need Updating
If you uploaded a file like a mp3, pdf, .doc prior to when the certificate is received, like images, the URL that was generated and shared may need to have the URL updated.
Custom Domain Name Settings
Domain Mapping is available for all Pro plans and your blog will remain secure when the new name is applied to it. The domain name needs to be set up securely with the CNAME pointing to your Typepad domain name (example.typepad.com). If the CNAME is not set up correctly, it may display as not secure. If you set up Domain Masking instead of Mapping, this will also disrupt the security certificate from working as expected.
A great, free, resources to use to find out what is causing the break is www.whynopadlock.com.
If you have followed all of these steps and your blog is still displaying as not secure, you can reach out to the Typepad Support Team by opening a Help Ticket and we'll be happy to further assist you.