Multiple Case Statements with Aliases - FROM keyword not found where expected - oracle

Question

Here's my code below. When I remove the aliases from the case statements the code runs just fine, and if I leave the alias on the case statement right before the FROM it still works as well. The error I'm getting is FROM keyword not found where expected.
SELECT
HST."HST_DBT_NO",
HST."HST_FLDB",
HST."HST_DATE",
OLI."OLI_FRST_SCHED_DATE",
A."REFERRAL_AMOUNT",
DBT."DBT_FLD_06",
(DBT."DBT_REFERRAL_DATE" - D."DEM_DOB")/365,
(CASE
WHEN A."CLIENT_REF_NUM_1" IS NULL THEN 'NC'
WHEN A."CLIENT_REF_NUM_1" IS NOT NULL THEN 'C'
ELSE NULL
END) AS Check,
(CASE
WHEN A."CLIENT_REF_NUM_2" = 'Checkless Installment Loan' THEN 0
WHEN A."CLIENT_REF_NUM_2" = 'Smart Installment Loan' THEN 0
WHEN A."CLIENT_REF_NUM_2" = 'California Payday Loan' THEN 0
WHEN A."CLIENT_REF_NUM_2" = 'California Checkless Loan' THEN 0
WHEN A."CLIENT_REF_NUM_2" = 'DSI Loan' THEN 0
WHEN A."CLIENT_REF_NUM_2" = 'Mississippi Checkless Loan' THEN 0
WHEN A."CLIENT_REF_NUM_2" = 'Mississippi Payday Loan' THEN 0
WHEN A."CLIENT_REF_NUM_2" = 'PLS Choice Loan' THEN 1
WHEN A."CLIENT_REF_NUM_2" = 'PLS Checkless Choice Loan' THEN 1
WHEN A."CLIENT_REF_NUM_2" = 'Wisconsin Checkless Loan' THEN 1
WHEN A."CLIENT_REF_NUM_2" = 'Wisconsin Installment Loan' THEN 1
WHEN A."CLIENT_REF_NUM_2" = 'Indiana Payday Loan' THEN 1
WHEN A."CLIENT_REF_NUM_2" = 'PLRA Loan' THEN 1
WHEN A."CLIENT_REF_NUM_2" = 'Indiana Checkless Loan' THEN 1
ELSE NULL
END) AS Veritec,
(CASE
WHEN SUBSTR(DBT."DBT_FLD_06",LENGTH(DBT."DBT_FLD_06")-1,2) = 'CI' THEN (SUBSTR(DBT."DBT_FLD_06",LENGTH(DBT."DBT_FLD_06")-5,4)*1)-1
WHEN SUBSTR(DBT."DBT_FLD_06",LENGTH(DBT."DBT_FLD_06")-1,2) = 'SI' THEN (SUBSTR(DBT."DBT_FLD_06",LENGTH(DBT."DBT_FLD_06")-5,4)*1)-1
WHEN SUBSTR(DBT."DBT_FLD_06",LENGTH(DBT."DBT_FLD_06")-1,2) = 'CD' THEN (SUBSTR(DBT."DBT_FLD_06",LENGTH(DBT."DBT_FLD_06")-5,4)*1)-1
WHEN SUBSTR(DBT."DBT_FLD_06",LENGTH(DBT."DBT_FLD_06")-1,2) = 'SD' THEN (SUBSTR(DBT."DBT_FLD_06",LENGTH(DBT."DBT_FLD_06")-5,4)*1)-1
ELSE (SUBSTR(DBT."DBT_FLD_06",LENGTH(DBT."DBT_FLD_06")-3,4)*1)-1
END) AS PriorLoans,
(CASE
WHEN OLI."OLI_FREQUENCY" = 'W' THEN 'WEEKLY'
WHEN OLI."OLI_FREQUENCY" = 'B' THEN 'BI-WEEKLY'
WHEN OLI."OLI_FREQUENCY" = 'V' THEN 'TWICE PER MONTH'
WHEN OLI."OLI_FREQUENCY" = 'M' THEN 'MONTHLY'
ELSE NULL
END) AS PayFrequency,
(CASE
WHEN OLI."OLI_PAYMENT_AMOUNT" > A."REFERRAL_AMOUNT" THEN 'Single Payment'
WHEN OLI."OLI_PAYMENT_AMOUNT" <= A."REFERRAL_AMOUNT" THEN 'Installment'
ELSE NULL
END) AS Type,
(CASE
WHEN HST."HST_DATE" - OLI."OLI_FRST_SCHED_DATE" < 5 THEN 1
WHEN HST."HST_DATE" - OLI."OLI_FRST_SCHED_DATE" >= 5 THEN 0
ELSE NULL
END) AS FirstPayment
FROM "CSS"."HST" HST
LEFT OUTER JOIN "CSS"."ACTUARY_NUMBERS" A
ON HST."HST_DBT_NO" = A."DEBTOR_NO"
LEFT OUTER JOIN "CSS"."DEM" D
ON HST."HST_DBT_NO" = D."DEM_DBT_NO"
LEFT OUTER JOIN "CSS"."DBT" DBT
ON HST."HST_DBT_NO" = DBT."DBT_NO"
LEFT OUTER JOIN "CSS"."OLI" OLI
ON HST."HST_DBT_NO" = OLI."OLI_DBT_NO"
WHERE (HST."HST_TYPE" = 'SC')
AND (HST."HST_DATE" = {ts '2015-04-22 00:00:00'})
AND (HST."HST_FLDB" = 'PSD')
AND (D."DEM_DOB" IS NOT NULL)