ASP classic POST multipart -- 2

I need to improve classic ASP code, which performs HTTP POST request, multipart with an attachment and payload information such as text and / or json. The ASP code generates HTTP content to send to a REST service, but it is returning the message: "The request content was malformed: Unexpected end of multipart entity " / **** Content sent with POST *** / ---------------- 010201080703010401070605 Content-Disposition: form-data; name = "className" Acquirer ---------------- 010201080703010401070605 Content-Disposition: form-data; name = "properties" { "code": "2052776", "amount_transaccion": 141.46, "codigo_tipo_impresion": "2" } ---------------- 010201080703010401070605 Content-Disposition: form-data; name = "file"; filename = "E: / data / Clientes / PMP / 05 digitalization project / scrlv / vouchers / [login to view URL]" Content-Type: image / png (data) ---------------- 010201080703010401070605--