Object must implement IConvertible

I'm trying to upload a .pdf to an Oracle database. I'm getting this error when I try to upload.

Object must implement IConvertible

can someone explain this error?

It bombs out on:
OleDbCmdObj.ExecuteNonQuery()

Code:

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Dim Bid_Type As Integer
        Dim Post_to_Int As Integer
        Dim pdf_Upload As HttpPostedFile = pdfUpload.PostedFile
        Dim FileLength As Integer = pdf_Upload.ContentLength
        Dim FileByteArray(FileLength) As Byte
        Dim StreamObject As Stream = pdf_Upload.InputStream
        StreamObject.Read(FileByteArray, 0, FileLength)

Dim sqlCmd As String = "Insert Into PBSS.PBSS_BID(Bid_ID, Bid_Type_Code, Buyer_Name, Bid_Document, Post_To_Internet) Values(?,?,?,?,?)"
     
        Dim OleDbCmdObj As OleDbCommand = New OleDbCommand(sqlCmd, strConnection)

        OleDbCmdObj.Parameters.Add("@Bid_Id", System.Data.OleDb.OleDbType.VarChar, 5).Value = txtBidId.Text
        OleDbCmdObj.Parameters.Add("@Bid_Type_Code", System.Data.OleDb.OleDbType.Numeric, 2).Value = Bid_Type
        OleDbCmdObj.Parameters.Add("@Buyer_Name", System.Data.OleDb.OleDbType.VarChar, 45).Value = txtBuyerName
        OleDbCmdObj.Parameters.Add("@Bid_Document", System.Data.OleDb.OleDbType.Binary, FileLength).Value = FileByteArray
        OleDbCmdObj.Parameters.Add("@Post_to_Internet_ind", System.Data.OleDb.OleDbType.Numeric, 1).Value = Post_to_Int

        strConnection.Open()
        OleDbCmdObj.ExecuteNonQuery()
        strConnection.Close()

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