Problem installing new SSL certificate

When we try to install the SSL certificate through the asterisknow web interface and upload the cert asterisk just crashes and needs a manual restart for the web interface to work again.

Also it asks for a .PEM file while we have received a .crt, we converted the .crt to .PEM but now it gives the following error:
SSL: Private key does not match the certificate public key, reason: error:0906D06C:PEM routines:PEM_read_bio:no start line /etc/ssl/pem/raa.pem