Customer has access to Account "124567 Company A" using the email address email@example.com.
The same customer was given access to another NetSuite account. For instance, Account 012456 Company B, using the same email address (firstname.lastname@example.org). When the customer log in to his account, he cannot see the role/s assigned to him for Account 012456 Company B in the "View All Roles" page.
To be able to resolve this, the user would need to sync all his NetSuite accounts by resetting his password using the Security Questions.
Make sure that the Security Questions are set up under Home > Settings Portlet > Update Security Questions. Once the Security Questions are set up, the user can reset his password using the "Forgot your Password?" link on the NetSuite login page.