Whatsapp adding contact error

I had been uninstall and reinstall whatsapp many times , deleting the folder and restart the smartphone but whatsapp didn't show my contact in the list.

As for instant , Whatsapp search my Contact added at the phone and add the contact number into Whatsapp contact accessing their server but it doesn't.

Whatsapp cannot find any contact at all as if Whatsapp cannot search Phone Contact to add into whatsapp Contact.

Can I manually add or export the contact like to .xml or .vcf and let Whatapp to import those .xml or .vcf ? Something similar with Ms outlook ?