My CTE runs in an infinite loop for a specific customer and I am not able to find out why.

Here is the query:

;WITH ClassTree
           AS (SELECT ID, NAME, Parent_ID
               FROM   TableName
               WHERE  ID = 1
               UNION ALL
               SELECT T.ID, T.NAME, T.Parent_ID
               FROM   TableName T WITH (NOLOCK)
                      JOIN ClassTree
                        ON Parent_ID = ClassTree.ID
)
SELECT * FROM ClassTree



Question: Why is my MacBook Pro's screen going black for a second?
Answer: Ive had similar problem,
The inverter and screen has been replaced by warranty.
Does it happens when you change angle of your lid?