For now, the best thing to do is join the IRC channel and ask a question. Stick around a while. It may take some time for someone to notice.

First, some sanity checks. If you check the status of the plugin in the terminal, it should read something like this:

• $ sudo /usr/sbin/update-pepperflashplugin-nonfree --status
  Flash Player version installed on this system  : 13.0.0.nn
  Flash Player version available on upstream site: 12.0.0.nn 

If you check the browser's about:flash , it should say something like

• About Flash
  
  Chromium        34.0.X.Y (Ubuntu nn.nn aura)
  OS              Linux
  Flash plugin    13.0.0.nn /usr/lib/pepperflashplugin-nonfree/libpepflashplayer.so 

Next, if running "chromium-browser" from a terminal works but running from the icon in the dash or from search doesn't, then you should un-pin the chromium icon from the dock, then open a terminal and run,

•  grep -l chrom ~/.local/share/applications/*desktop |while read f; do rm -v $f; done 

then search for it in the dash and run it normally. Feel free to pin again.