When you get a problem like this, start by eliminating possibilities.
Comment out most of the query, and see what you get:
SELECT
EnID
FROM
ClassEnrollments
If that produces records, add a bit back:
SELECT
EnID
,Engineer.Lastname AS Lastname
,Engineer.Firstname AS Firstname
FROM
ClassEnrollments
INNER JOIN Engineer ON Engineer.EID = ClassEnrollments.EID
And see what that produces. If it all looks good, add some more:
SELECT
EnID
,Engineer.Lastname AS Lastname
,Engineer.Firstname AS Firstname
,Faculty.Lastname AS Flastname
,Faculty.Email AS email
FROM
ClassEnrollments
INNER JOIN Engineer ON Engineer.EID = ClassEnrollments.EID
INNER JOIN Faculty ON Engineer.FID = ClassEnrollments.FID
And so on. When it fails, look closely at the data you just added and see if there is anything obvious.