My Lumina 635 wont send nor receive images

[Colin321]

I was sending and receiving images on my Lumina 635 nicely and suddenly I discovered people weren't getting my images, not I receiving them!
This seemed to coincide with my installing "Whatsapp" but the phone shop say its nothing to do with "Whatsapp".

The phone isn't new, its in fact 6 years old, but it is a fine phone and never lets me down.

Any ideas please?

Col