This is a step-by-step tutorial on how to fix Unknown error code during application install: -24 on Android
Cause
This is as a result of a clash at the /data/data folder. While Installing an app, a folder is created for this app at the /data/data directory . If this folder isnt removed during uninstallation and you wish to re-install the app later, you could get this error.
How to fix
Method 1: Direct Downloading of the application
Try download the apk of the application online instead of from Google Playstore then install