Godaddy SSL Certificate on Plesk Panel
When you buy a certificate from godaddy it usually show error on firefox
GoDaddy FireFox Error: sec_error_unknown_issuer
and for other browser you get error that the issuer is unknown.
To fix it you have download:
Go Daddy Certificate Bundles (for cPanel, Plesk, Apache 1.x and 2.x installation only)
from
https://certs.godaddy.com/Repository.go
and you have to copy it to the file
/usr/local/psa/admin/conf/ca-bundle.crt
at the end of the file.
Then you have to stop and start server (not restart).
It should work now without any problems.