After downloading the app, it shows me Package File Is Invalid. I'm using Xperia L. I cleared cache & data from Settings > Apps > Play store
Why ?
Which app you are trying to install?
Is this happening with all the apps or some specific app? If it's the problem with some specific app, then it's the fault of developer or google play store. In that case comment and inform the developer about the same.
It is working now after I rebooted it.
I was using it continuosly since Wednesday, maybe its due to that