While enabling the feature “payment instruments” getting an error message as “not allowed”.So that user is not able to get into the checkout and myaccount pages.

Solution:
Go to setup ->Users/Roles ->Manage roles
kindly add the following and set the level to “Full” for the customer center role. :
- Payment Card
- Payment Instrument
- Payment Card Token
- Payment Methods
- Credit Card
Note: You may set the permissions to Full in order to not encounter any errors but, you may still modify it to a lower permission level.