I've had the same issue and it has been pretty difficult to resolve, even with the instructions above, because of spaces and quotes. For those who face the same issue, here is the shortcut target that I entered.
"C:\PortableApps\Opera DevR\launcher.exe" --ppapi-flash-path="C:\Windows\system32\Macromed\Flash\pepflashplayer32_16_0_0_228.dll" --ppapi-flash-version="18.104.22.168"
Now it works, after hours of struggle...
Thanks to all who contributed.