I have zero cache and 75MB and yet I'm unable to download an 8MB app. I've already deleted all my important apps to make space for it and yet that annoying message keeps showing up. PLEASE HELP. Im using an Xperia e3.
Go to Settings>Apps>All and uninstall Google Play Store. This will uninstall only updates for the new version, and replace it with the old version. Then you can download without the "Insufficient Storage ERROR".