Approximately six months ago several web sites began to lose their styles gradually and finally some of them entirely stopped working in Opera although they work in other browsers. All this seemed to look like conspiracy against Opera-Presto.
Today I realized what the problem is: all of the failing sites are using HTTPS to retrieve their CSS and JavaScript Files, and it seems that some of important certificates have expired.
Opera complains in Dragonfly:
No request made. All data was retrieved from cache without accessing the network.
As the certificates aren't updated automatically, I need to import them manually. But where to download up-to-date root certificates from?
It accepts:
- crt
- usr (x509)
- p7s (pkcs 7 signed)
- p7 (pkcs 7)
- p12 (pkcs #12 with security key)
- pem
Update – the real solution
In reality it wasn't anything wrong with Opera and it's certificates storage!
The real bad guy was the Eset NOD 32 antivirus, which messed in some way with SSL connections, although it shouldn't. I understood it when almost all SSL web sites stopped working in any browser except Tor Browser. Turning NOD32 off didn't solve problem. I had to remove it completely and install it again.
What to do with an answer? Let it be here!
Best Answer
According to Opera, Opera used to run its own root store but it ceased doing that in 2013. Details below:
Below are a couple of certificate sites where you can download root certificates:
Digicert
Geotrust
There are instructions here, here and here to install a root certificate after downloading it.
Opera provides notifications for the certificates needed through screens like "Invalid Certificate" "Certificate has expired"... so forth. If it does this too many times, it's a bug and you can try turning off the notifications like they say here.
Though I haven't used it, there is even a blog with the script to search list certificates supported by Opera.