If you see the message Error -24
If your operating system is Android version 4.4, and you have tried to install WhatsApp without success, it may be generated a folder that keeps you from reinstalling the app.
This folder is called com.whatsapp, and is located in / data / data (as explained on the site WhatsApp). The only two ways to remove it are:
Have a rooted phone (in which case you can find the folder and delete)
Reset the phone (Settings> Backup and Restore> Factory data reset)
Warning! Remember to reset the phone to factory data means losing all data (phone numbers, messages, call log, saved files, and so on) it contains. Before you make a full backup of the contents of your mobile phone.