My apache error log shows a large number of SSL Stapling errors after a Graceful restart: Code: Graceful restart requested, doing restart ssl_stapling_init_cert: no responder URL I did google SSL Stapling but didn't find much information. I have just upgraded the server and I have never encountered this error. The https:// pages are secure but I don't understand what this error signifies and whether it is causing page failures for my customers? I am running CENTOS 6.5 x86_64, Apache 2.4.7 with PHP 5.5.8. Any ideas?