Are you missing your intermediate certificates? Get the chain certificates for a specific certificate.
If you have missing chain certificates or don't know what they are, you can use the certificate chain composer tool above to fetch them. Simply paste in the contents of your .crt file and it will return your complete certificate including the intermediate certificates. You can then install them on your web server or CDN provider. It will also return the decoded certificate.
If your certificate is not valid you will see the following error.
The list of SSL certificates, from the root certificate to the end-user certificate, represents a SSL certificate chain, or intermediate certificate. These must be installed to a web server along with a primary certificate. If they aren't installed web browsers will display an "Invalid certificate" or "certificate not trusted" error. You can use our SSL Certificate Check tool to validate your chain.