Dim P As Product
Dim FileRec As Integer
P.Name = txtProdName.Text
P.Code = txtProdCode.Text
P.Date = txtDate.Text
P.Quantity = txtQuantity.Text
P.Measure = txtMeasure.Text
P.Price = txtPrice.Text
If (txtPrice.Text <> "") And (txtQuantity.Text <> "") Then
P.Cost = txtPrice.Text * txtQuantity.Text
Else: P.Cost =  0 
End If
Open fMain.txtFilePath.Text For Random As # 1  Len = Len(P)
FileRec = LOF( 1 ) / Len(P) +  1 
Seek # 1 , FileRec
Put # 1 , , P ' Тут вылетает по ошибке Bad Record Length
Close # 1 

Type Product
    Name As String *  15 
    Code As String *  10 
    Measure As String *  10 
    Date As Date
    Quantity As Double
    Price As Double
    Cost As Double
End Type