I was literally trying to install this for close to a fortnight. Westpac bank and Samsung weren't able to assist! 

Thank you so much!I followed option B and successfully installed Samsung pay and added my cards successfully!You're a legend!

Same issue, have reset phone, reset password.All permissions needed, allowed.Couldn't start Samsung Wallet. Something went wrong. Please try again.Worked prior to UI 6.0 UpdateUsing Google wallet in the interim.