Flash player install on Mac OS X 10.9.2

Hello,

I'm trying to install the new version 20 of Flash player but it keeps stopping at 50% donwloading...

I had the version 12 but my website (wordpress shoponline) for couple of days shows white empty pages, I guess the problem is coming from flash player so I uninstalled my old version but now impossible to install the new one...

Help?

Thanks a lot