I have been asked this question several times that how to resolve App download issue in Android One Mobile phones.
I also got the same issue with my Spice Dream UNO (Mi-498) Android one and resolved it successfully. I am writing step by step solution which I followed to resolve this issue. If you still face the same issue, write in comment section.
Android One is a standard created by Google for Android systems, mainly targeted at people buying their first smartphone and customers in the developing world. [As per wikipedia]
Following 3 Mobile phones launched with Android One:
Steps to resolve App Download Issue:
You have to clear cache and data of Google Play Store App & Download Manager.
Visit Menu > Go to Settings > Click on Apps > Tab over to All option
Now select the Google Play Store app and then tap “Clear Data” & “Clear Cache” option.
Just like Google Play Store, select Download Manager and tap “Clear Data” & “Clear Cache” option.
Now try to download any app from your android one mobile phone.
This solution has worked for me. If you face any problem, write to us in comment section.