It's Opera 23!
Opera 23 uses the system's proxy settings, so make sure to check them as mentioned earlier. Also, check the time and date etc. as mentioned earlier.
But, just in case it's a bug in Opera 23, see this post. Click the "Opera Developer offline package for Windows" link to download the installer. Launch the installer, click "options", change the "install path" to a folder on your desktop, set "install for" to "Standalone Installation (USB)" and install. Launch opera inside the folder on your desktop whenever you need to load that Opera.
That Opera won't interfere with your normal Opera install at all. But, it will allow you to test to see if anything has been fixed in the developer builds.
You can try the same thing with the Next Version.
You can try the same thing with Opera 23 from opera.com to see if it's just something messed up with your regular Opera 23 profile. If so, we can investigate further.