Opera version: 42.0.2393.94
Os: Ubuntu 16.10 64bits
Note: Preintalled pepperflashplugin-nonfree in your distro.
modify as root; "usr/x86_64-linux-gnu/opera/resources/pepper_flash_config.json"
{
"PepperFlashPaths" : [
"/usr/lib/flashplugin-installer/libpepflashplayer.so",
"/opt/google/chrome/PepperFlash/libpepflashplayer.so"
]
}
-- With your "libpepflashplayer.so" Location, save, restart