Problem:
Yesterday my WhatsApp icon on the home screen had greyed out. It had turned into that translucent grey colour and it seemed to be not responding. The app would not launch even from the Application List, obviously.
Solution:
Turn on the backup
Settings > Backup > App + Settings > Backup Now
Cause:
I remembered that the last activity that I was asked by the OS to do was to backup. It seems I had started the backup process, but it was too slow, so I switched off the Wifi and went to sleep. I just restarted that process of backup and WhatsApp icon was in its normal state in around 10 minutes. It looks like WhatsApp is one of the apps that performs a backup during this operation and it remains in an unusable state during the initial part of its backup process.
Yesterday my WhatsApp icon on the home screen had greyed out. It had turned into that translucent grey colour and it seemed to be not responding. The app would not launch even from the Application List, obviously.
Solution:
Turn on the backup
Settings > Backup > App + Settings > Backup Now
Cause:
I remembered that the last activity that I was asked by the OS to do was to backup. It seems I had started the backup process, but it was too slow, so I switched off the Wifi and went to sleep. I just restarted that process of backup and WhatsApp icon was in its normal state in around 10 minutes. It looks like WhatsApp is one of the apps that performs a backup during this operation and it remains in an unusable state during the initial part of its backup process.