Error when creating a view with a CTE

You are missing the first AS after the CREATE VIEW:

CREATE VIEW [dbo].[VW_THIRDPARTY_SLA_REPORT_MONTHLY_GP_NONAGGREGATE] 
AS --- this is missing
  With partitioned
  AS 
  (
   Select 
      B.MSH7_DateTimeOfMessage,
      B.PID2x1_PatientIDExternal,
      B.PID3x1_PatientIDInternal,
      B.PID5x1_PatientName_FamilyName,
      B.PV3x2_AssignedPatientLocation_Room,
      A.OBR4x2_UniversalServiceID_Text,
      A.OBX3x2_ObservationIdentifier_Text,
      A.OBR24_DiagnosticServiceSectionID,
      A.OBR6_RequestDateTime,
      C.TestName,
      C.PriceBaseline,
      D.Contract,
      Row_NUMBER() OVER(Partition By [ORC3_FillerOrderNumber], [OBX3x2_ObservationIdentifier_Text] order by [ORC9_DateTimeOfTransaction]) as seq
   From [NWLHPathApp_DataWarehouse].[dbo].[PathologyHL7_Detail] A
   LEFT OUTER JOIN [NWLHPathApp_DataWarehouse].[dbo].[PathologyHL7_Header] B ON A.[DETAIL_ID] = B.[HEADER_ID]
   LEFT OUTER JOIN [NWLHPathApp_DataWarehouse].[dbo].[PathologyHL7_View_TFCData] C ON A.[OBR24_DiagnosticServiceSectionID] + A.[OBX3x1_ObservationIdentifier_Identifier] = C.[KEY]
   LEFT OUTER JOIN [NWLHPathApp_DataWarehouse].[dbo].[PathologyHL7_LocationDetail] D ON B.[PV3x1_AssignedPatientLocation_PointOfCare] = D.[PracticeCode] 

   )
   Select *
   from partitioned  
   where seq =1 

It might be helpful to point out that you cannot seemingly add view column titles at the same time as using CTE. (this wasted a few minutes of my time)

create or replace force editionable view "MYVIEW"
  --("Field1", "Field2")
as 
with results as (
    select cal.field1,cal.field2  from mytable cal
) 
select field1,field2 from results
;

if you uncomment the ("Field1", "Field2") column declaration above, this fails.

You need AS after CREATE VIEW:

CREATE VIEW [dbo].[VW_THIRDPARTY_SLA_REPORT_MONTHLY_GP_NONAGGREGATE] 
AS
With partitioned ...