My WhatsApp Problem Sorted - Reset Method

How?

This is how: Google says - 

Right Click Start, then head to Settings > Apps

Select Apps & Features

From the Apps list, select WhatsApp and click Advanced Features

Select the Reset Button

Open WhatsApp and check if it's working.

Note: It did warn that it might lose data, but I was OK

Kipling's Six Serving Men

I Keep six honest serving-men:
(They taught me all I knew)
Their names are What and Where and When
And How and Why and Who.