WhatsApp not connecting on new iPhone 6 Plus
Hello there,
I switched from iPhone 4S to iPhone 6 plus using only iTunes (I don't use iCloud). Everything works fine, except WhatsApp which is constantly "Connecting". The iPhone is unlocked (I didn't buy it with a SIM) and I tried entering the settings for my carrier in the Cellular Data menu, but nothing changes, only WhatsApp from all apps isn't working. I really don't want to reinstall it, because I don't want to lose all my conversations. If anyone has an idea on how my problem might be solved, please feel free to share.
Thanks.
iPhone 6 Plus, iOS 8.3, null