I tried this simple trick and it worked for me. Check the path in your system accordingly
64-bit system
cp /usr/lib64/mozilla/plugins/libflashplayer.so /usr/lib64/midori/.
32-bit system
cp /usr/lib/mozilla/plugins/libflashplayer.so /usr/lib/midori/.
Close Midori(if open) and open it again..flash player will work..Do let me if it worked
