Android package file invalid - what to do?

Invalid package file on Android - so you fix the error

Use the tips below to try to fix this error:

First, try restarting your smartphone. If possible, you can also remove the battery. In this way you can fix small errors in the buffer.
If that doesn't help either, take a look at "Software Update" under "Settings"> "Via phone". An update may be available for your phone.
In general, you should make sure that you have enough free space on the device.
Uninstall apps that are not being used or under "Settings"> "Storage" set the "Default storage location" to the "SD card", if available.

If these tips did not help, open the "Settings" of your Android smartphone and switch to the installed apps. Search for "Google Play Store" and "Google Play Services" here.
Tap on the name and then on the "Force stop" and "Delete data" buttons. All erroneous data of the apps will be deleted. The next time they are started, they are created so that nothing is lost.
In addition, under "Google PlayStore" you can reset all updates of the Play Store via "Uninstall updates".
Then open the Play Store and try again to download the desired app.
If the error persists, the problem is probably with the app itself. You can alert the developer to this error or wait for a new version of the app to appear.

If you want to visually tidy up your smartphone, you can hide unused Android apps. This guide is based on Android 4.4.2.N.