The Weird and The Wonderful

IIf
(TX.TX_TYPE="R",
  IIf
  (TX.TX_MOSTYPE="P",
    IIf
    (TX.TX_DEST_STATUS="A",
      "PO Receipt",
      IIf
      (TX.TX_DEST_STATUS="U",
        "PO Receipt Hold",
        "Other"
      )
    ),
    IIf
    (TX.TX_DEST_STATUS="A",
      "WIP Receipt",
      IIf
      (TX.TX_DEST_STATUS="U",
        "WIP Hold",
        "Other"
      )
    )
  ),
  IIf
  (TX.TX_TYPE="I",
    IIf
    (ISNULL(RTRIM(TX.TX_MOSJOB)) Or RTRIM(TX.TX_MOSJOB)="",
      "Shipment Return",
      "Reverse Issue"
    ),
    IIf
    (TX.TX_ORIGIN_STATUS=TX.TX_DEST_STATUS,
      "Loc Transfer",
      IIf(TX.TX_ORIGIN="SCRAPPED",
        "Reverse Scrap",
        IIf
        (TX.TX_ORIGIN_STATUS="J",
          "Count Adj Up",
          IIf
          (TX.TX_ORIGIN_STATUS="D",
            "PN Change To",
            IIf
            (TX.TX_ORIGIN_STATUS="I",
              "Reverse Unplanned Issue",
              IIf
              (TX.TX_ORIGIN_STATUS="A" And TX.TX_DEST_STATUS="U",
                "Hold",
                IIf
                (TX.TX_ORIGIN_STATUS="U" And TX.TX_DEST_STATUS="A",
                  "Off Hold",
                  "Other"
                )
              )
            )
          )
        )
      )
    )
  )
) AS [Transaction Type]

CASE WHEN TX.TX_TYPE = 'R' AND TX.TX_MOSTYPE = 'P' AND TX.TX_DEST_STATUS = 'A' THEN 'PO Receipt'
	 WHEN TX.TX_TYPE = 'R' AND TX.TX_MOSTYPE = 'P' AND TX.TX_DEST_STATUS = 'U' THEN 'PO Receipt Hold'
	 WHEN TX.TX_TYPE = 'R' AND TX.TX_MOSTYPE = 'P' THEN 'Other'
	 WHEN TX.TX_TYPE = 'R' AND TX.TX_DEST_STATUS = 'A' THEN 'WIP Receipt'
	 WHEN TX.TX_TYPE = 'R' AND TX.TX_DEST_STATUS = 'U' THEN 'WIP Hold'
	 WHEN TX.TX_TYPE = 'R' THEN 'Other'
	 WHEN TX.TX_TYPE = 'I' AND ISNULL(RTRIM(TX.TX_MOSJOB),'')  = '' THEN 'Shipment Return'
	 WHEN TX.TX_TYPE = 'I' THEN 'Reverse Issue'
	 WHEN TX.TX_ORIGIN_STATUS = TX.TX_DEST_STATUS THEN 'Loc Transfer'
	 WHEN TX.TX_ORIGIN = 'SCRAPPED' THEN 'Reverse Scrap'
	 WHEN TX.TX_ORIGIN_STATUS = 'J' THEN 'Count Adj Up'
	 WHEN TX.TX_ORIGIN_STATUS = 'D' THEN 'PN Change To'
	 WHEN TX.TX_ORIGIN_STATUS = 'I' THEN 'Reverse Unplanned Issue'
	 WHEN TX.TX_ORIGIN_STATUS = 'A' AND TX.TX_DEST_STATUS = 'U' THEN 'Hold'
	 WHEN TX.TX_ORIGIN_STATUS = 'U' AND TX.TX_DEST_STATUS = 'A' THEN 'Off Hold' ELSE 'Other' 
END AS Transaction_Type	

As you wrote:

Everything makes sense in someone's mind

.RedirectStandardOutput = False

Console class members that work normally when the underlying stream is directed to a console might throw an exception if the stream is redirected, for example, to a file. Consequently, program your application to catch System.IO..::.IOException if you redirect a standard stream.