I don't understand the term "can not" - what happens when you try?
Since you mention a "new Sony" I assume that it runs Windows 7. Flash Player and W7 are compatible, but only on 32-bit browsers. If you want to run Flash Player on a 64-bit browser, you need to download the 10.2 "Square" beta version.
I believe it is a linux system. There is no browser for the e-reader, just a generic web access. It's not like it has a windows interface or anything. On the sony website it said it runs linux, but it might have meant something other than the operating system, or I might have misread it. I have tried downloading ALL the options for different systems. All of them have a similar message. Thinking about returning it.