The "Missing data files" error may appear when the Little Reader Touch app's system data or media library was deleted or modified accidentally. This error may also appear if Little Reader Touch crashed the first time it is launched (after installing the app).

To fix the error, you need to reset the app's lesson library by following these steps:

1. Open the Little Reader Touch app and go to Settings by tapping the cog wheel button in the home screen

 OR 

2. In the Settings screen, find and tap Reset Lesson Library

3. Tap Yes to confirm

4. Wait a few minutes as Little Reader Touch resets your lesson library

5. Once the process has finished, check if you can now open and use Little Reader Touch without getting any further problems