What have you tried to research to find a solution? Using some key words from your issue I have searched google and found a whole host of *possible* causes and solutions. Obviously I can't say much else as I don't know anything about your system, but I doubt many people can shed much light on this without knowing much more about your system.
Also, I don't mean to appear rude, but I never considered this Group akin to the Stack Exchange network. Perhaps you can find useful solutions on ServerFault or StackOverflow?
p.s.> does this help:
http://unix.stackexchange.com/questions/266838/troubles-with-certificates
And I read a lot of topics about this refering to mod_nss errors/issues.