1. Try to clear Samsung App Store data (Settings-App Manager-All-Samsung App Store-Clear Data).
2. After deleting the account from the phone, try logging in again.
3. Try to switch Internet access mode (data access/wireless network).
4. Change other Samsung account login attempts.
5. Back up data (contacts, text messages, photos, etc. ) and restore factory settings (Settings-General-Reset-Restore factory settings).
If the problem still exists, it is recommended that you take your mobile phone, purchase invoice and warranty card to the local Samsung after-sales service center for testing. Please visit:
It is recommended that you apply for "booking to the store" in Samsung official website and enjoy priority maintenance service:/pre-order.
After the appointment is successful, please bring your machine, invoice and warranty card to the service center you reserved on time.