Published Android apk gives error “Package file was not signed correctly”

Question

I recently uploaded my application to the android market however it\'s refusing to run when downloaded due to the error

Package file was not signed co

Answer 1

On a tablet, note that if you install a debug version of the app and then uninstall it as normal (dragging to trash until it says "uninstall") that is not enough. Because tablets have the potential for multiple users, you HAVE to go to

 Settings > Apps > All

and then scroll all the way to the very bottom. There, you will see your app. Tap it, and then hit Menu in the action bar (the three dots), and then uninstall for all users. Then you'll be good to go.