Sync is currently experiencing problems, but only for WhatsApp?

[aidannn]

So earlier today my phone died and when i recharged it and turned it on, i was surprised to see that in Whatsapp, all my contact's names have been changed to numbers. I went to the settings app to see if there was a problem with the sync and it said that it was experiencing problems. But the thing is, Whatsapp is the only one that seems to have an error, Facebook and Google work fine. What do i do?