In order to monitor our application at client sites, we have added a monitoring page (using apache). To prevent preying eyes, we require clients to identify them selves using a client certificate. This used to work until a few weeks ago, but now we are having problems using firefox. It keeps stating a SSL_ERROR_HANDSHAKE_FAILURE_ALERT error, and we cannot accessing the pages. I have already added our Root CA and intermediate CA (used to sign the client certs) in both firefox and the windows certificate store, But the problem is not yet resolved. The subdomain is protected with a an Organization Validated certficate from an official CA authority. Apparently we are missing something, but i can't see what is causing this issue. If i disable the requirement for a client certificate, the site is accessible, but that is not really an option here.