That error message is saying that another tax return has
been filed claiming an education credit for the same student as shown on your
return.
In order to fix this on your tax return so that you can
electronically file it, you must remove the education credit that is being
claimed.
Or, you can leave the credit on your return and file it by
mail. Then, when the IRS is processing
your return they will examine both your return and the one that is claiming the
same student to determine which one was filed correctly to claim the credit.