SELECT
[Stock Conversion Items].SCID,
[Stock Conversion Items].[Result PC],
[Stock Conversion Items].[Quantity],
[Stock Conversion].[Date],
[products/stock].[Description]
FROM
[Stock Conversion Items]
INNER JOIN [Stock Conversion]
ON [Stock Conversion Items].SCID = [Stock Conversion].SCID
INNER JOIN [products/stock]
ON [Stock Conversion Items].[Result PC] = [products/stock].[Product Code]
ORDER BY [Stock Conversion Items].SCID;
このコードはかなり自明です。基本的に、まったく解決できない構文演算子エラーが発生します。