iphone 5 not able to download apps

[wwest11]

when i try to download a app a 'unknown error' message comes up. password it right as i can log onto apple, but cant download

 

[willerz2]

Try logging off your Apple ID, reboot your device and re-input your credentials again.

 

[scifan57]

Have you checked in Settings>General>Restrictions>Installing Apps to see if installing apps is turned on?

 

[annaharris]

Just check after restart it. If the problem is still there, then you should go at Apple store to solve this problem.