"Certificate file is not valid" when enabling "Apache SSL website"

If I try to access https:// in the browser, I get the following output in Firefox, Chrome and IE (http working fine):

Secure Connection Failed
Error code: SSL_ERROR_RX_RECORD_TOO_LONG

After a virtualmin restore, I can’t seem to enable SSL through Edit Virtual Server -> Enabled Features -> Apache SSL website enabled? When I enable it, I get the following error:

Adding new SSL virtual website …
… certificate file is not valid : Line 32 does not look like PEM format

I’m currently researching the CLI process of this to give me further insight, but any pointers are very much appreciated to accelerate my learning. I’m not seeing much information in ‘/etc/httpd/httpd.conf’ Maybe there is a webmin configuration file that holds more information?