App isn't installed but it did.

[hh7x]

I'm using Honor 7x and currently installing several apps such as WhatsApp and Wattpad. It did appear on my homescreen and went well at first but then, when I wanted to click on the icon again, it showed "App Isn't Installed". I'd tried to update the app and reboot my device. Well it worked but then it happened again after that. Anyone knows how to fix this? And why does it happen?