why I can't download/ upgrade an apps?

[iMore Question]

When I'm downloading an apps or upgrading it's always loading even the network is so fast

 

[kch50428]

Could be a number of things... Reboot the device... Log out of the places you can log in with your AppleID on the device... Reboot, log in again... Reset network settings... Consider restoring the device's iOS via iTunes if nothing else works.