If your organization has not provisioned any roles with SAML Single Sign On but has enabled it in your account users will not be able to login and will receive an error message similar to the one below.
My Organization Does Not Use SAML Single Sign On
Check with your NetSuite Admin and ask if they have enabled the SAML Single Sign-On (Setup -> Company -> Enable Features -> SuiteCloud).
As long as no one is using SAML Single Sign-On they should
uncheck this box (screenshot below).
Go to Setup > Integration > SAML Single Sign-on and click on Actions > Delete IDP Configuration
It may take a few hours for this change to propagate and after that period of time you should be able to login without any issues.
My Organization Uses SAML Single Sign On
If your organization is using Single Sign On then ask your Admin to make sure the following 3 permissions are enabled for your role.