Flash/ Netscape plugins don't work

You need to set MOZ_PLUGIN_PATH, for example like this:

export MOZ_PLUGIN_PATH="/usr/lib/mozilla/plugins"
The official Flash plugin is called libflashplayer.so .

You can either run that above line and run Midori in the same terminal afterwards or, for the long term, put it in ~/.bash_profile or /etc/profile.d or your respective distribution's place for this.