Dear Lauren,
I would split the task as you may have text entries within the line (RDR1.FreeTxt) and additional TextLines (RDR10.LineText).
Please try the following:
SELECT T0.[DocDate], T0.[DocNum], T2.[SlpName], T0.[CardCode], T0.[CardName], T0.[NumAtCard], T1.[U_CreditType], T1.[U_ClaimCategory],
T0.[U_RSWTotalCost], T1.VisOrder, T1.[ItemCode], T1.[Dscription], T1.[Quantity], T1.[Price], T1.[FreeTxt], T0.[Comments]
FROM ORDR T0
INNER JOIN RDR1 T1 ON T0.DocEntry = T1.DocEntry AND T1.LineType = 'R'
INNER JOIN OSLP T2 ON T2.SlpCode = T0.SlpCode
WHERE T0.[DocDate] >= [%1] AND T0.[DocDate] <= [%2] AND T1.[U_CreditType] Like '%%_%%'
UNION ALL
SELECT T0.[DocDate], T0.[DocNum], T2.[SlpName], T0.[CardCode], T0.[CardName], T0.[NumAtCard], '', '',
'', T1.AftLineNum, '', '', 0, 0, T1.[LineText], ''
FROM ORDR T0
INNER JOIN RDR10 T1 ON T0.DocEntry = T1.DocEntry AND T1.LineType = 'T'
INNER JOIN OSLP T2 ON T2.SlpCode = T0.SlpCode
WHERE T0.[DocDate] >= [%1] AND T0.[DocDate] <= [%2] AND T1.[U_CreditType] Like '%%_%%'
ORDER BY T0.[DocDate], T0.[DocNum], T1.[VisOrder]