Store Login Error

"My customer is using the correct login information, but gets an error and can't login: 'Unfortunately the information you entered is not correct. Please re-enter your information and try again.'"

Perhaps they are actually using an incorrect password. Try resetting their password. See Sites > Site Users. If this is a B2B storefront, make sure the User is Approved. See Sites > Site Users. The "User Account is Approved" box must be checked.