SQL & PL/SQL

I have been working on query that I keep getting this error on. I'm not sure why, because it is a valid field name in the view. When I run the inner joins on their own, they run with no problems. I'm just about out of resources. Can someone please help? Here is a copy of the script I have been working on. The boldface characters are where the errror is occurring.

SELECT
DISTINCT k.dataid AS folder_id,
k.name AS folder_name,
k.path AS folder_path,
s.name AS file_name,
s.dataid AS file_id,
m.event AS action,
trunc(m.auditdate) AS action_date
FROM
VDTreeFiles s
INNER JOIN
TDAudit a
ON a.dataid = s.dataid
INNER JOIN
VDAuditFileActivity m
ON a.dataid = m.dataid
INNER JOIN
VDTreeFolders k
ON a.dataid = k.dataid;