In some browsers like konqueror and old firefox verions we were getting this problem.
Unable to locally verify the issuer’s authority
To solve this you must use an intermediate certificate, to download this intermediate certificate you must contatct your provider, in our case was Verising https://knowledge.verisign.com/support/ssl-certificates-support/index?page=content&id=AR1735
Inspect your certificate to check the version you are using.
With this new cwertificate in hands create a “bundle” certificate; cat your_domain_certificate.crt intermediate_certifica.crt >> bundle.crt .
Configure your nginx with this new certificate
# SSL configuration
ssl_protocols SSLv3 TLSv1;