The certificate is not trusted in all web browsers. You may need to install an Intermediate/chain certificate to link it to a trusted root certificate. Learn more about this error. You can fix this by following Comodo's Certificate Installation Instructions for your server platform (use these instructions for InstantSSL). Pay attention to the parts about Intermediate certificates.
Note the link to Comodo's Apache OpenSSL instructions:
If I upload the ca-bundle file in the same /conf/cert directory where the site's key and crt are, then say Chained Certificate - Yes, CA Certificate Path = $SERVER_ROOT/conf/cert/ and CA Certificate File = $SERVER_ROOT/conf/cert/yourSERVERNAME.ca-bundle
I restart LSWS and then that tool, and the browser thinks no SSL has been installed.
I don't understand the explanation of CA Certiticate Path and File either.