Hi, I have just recently purchased a Samsung Galaxy S2, and I have one problem while trying to downloading some applications. Whenever I try to download a couple of applications (Facebook, Instagram, Skype, Temple Run etc.) I keep getting a little pop up message saying "Package File Is Invalid". I do not know what it means, I initially thought it meant my data/credit had run out, so I re-charged my mobile, and I am still getting the same pop up. I have taken it to two phone stores and they both have no idea what to do, they said to try a "Factory Data Reset". So I did that, and I am still getting the same pop up message. I have looked around on google, doing the things people have suggested like clearing the cache on the Play Store app, still not working. I have run out of idea's. Has anyone ever had this problem or know what to do? If you do, please respond. P.S It will let me download some applications, not all of them though & I had no problems downloading applications through my old Huawei mobile phone.