[Help] Installing apps?

[WPCentral Question]

I updated my nokia lumia 625 yesterday to windows 8.1 and now i can't download and install apps (like here maps, gmaps) from store. however i was able to download viber and wattsapp.I have also inserted a new SD card in my phone yesterday. Is something wrong with the card or my Phone??

 

[Matheus Teles]

try formatting the device, the same thing happened with my friend, and it was solved by formatting