Hi and welcome to our forum. Firefox is the browser that comes with wattOS R9 32 bit or 64 bit. Midori has issues... It is possible to use Chrome's pepperflash in Firefox. Look at this:
http://www.webupd8.org/2014/05/install-fresh-player-plugin-in-ubuntu.html BTW, You never said which version you were using, Microwatt Edition 32 bit or 64 bit or wattOS R9 32 bit or 64 bit. Hopefully, you checked the md5sum on the download. Please let us know what your computer specs are and what version you are using so we can help.