ssl_error crl

[Nogs]

Hello everybody,
I am a new in nginx and I need a help for crl config in my nginx.conf. 
About your information my ssl certificate is a trusted certificate by
commodore. 
And the certificate that users use for authentication is provided  by my own
Microsoft CA. 

In my configuration, if I activate ssl_crl  the authentication doesn't work
but if the line ssl_crl is commented it works.
At the line ssl_client certificate I put  the ca certificate who delivered
users certificate and my crl is a pem format
in bellow my conf
server_name yella.com;  
    ssl_certificate      /usr/local/etc/nginx/certs/fyella.crt;
    ssl_certificate_key  /usr/local/etc/nginx/certs/yella.key;
    ssl_client_certificate /usr/local/etc/nginx/certs/root.pem;
    ssl_verify_client on;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_prefer_server_ciphers on;
    ssl_crl                   /usr/local/etc/nginx/certs/crl.pem;


Best Regards

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,275827,275827#msg-275827