So I installed Lubuntu the other day replacing my Ubuntu installation. Lubuntu comes preinstalled with Chormium and not Firefox. While Chromium is great for every day use. I had a certain problem with it in Ubuntu which also occurs in Lubuntu.
Effectively, I get a message saying that the flash plugin has been blocked because it is out dated and it gives me the option to allow the site to access it this once.
I checked in my Synaptic Package Manager and as best I could tell, I had the latest version of flash installed, something Chromium apparently did see.
The reason for this as I learned is simple, Chromum has it's own Flash plugin install which resides in the following dir: /usr/lib/chromium-browser/plugins/ the plugin file is called libflashplayer.so.
However, if you run the command locate libflashplayer.so, you will find the system install of this file at /usr/lib/adobe-flashplugin/libflashplayer.so.
If you check the file sizes of these 2 files and the one in the adobe-flashplugin dir is bigger, that means you can simply copy that file to the chromium directory and solve the problem.
You could also choose to create a symbolic link instead of copying the file but I like to keep things simple.