Chosen Solution
When I tried to update my notification enabler app then my phone shows a message that is application is illegally modified. Due to this I can’t get my Whatsapp notification. What I do?
Whatsapp has a cloud backup feature. Use it to backup everything then Uninstall whatsapp and delete all the data related to it from your device . Then install it from an OFFICIAL SOURCE or install a modified firmware on your asha so that sideloaded apps will start to work.