Pdf cannot view

After I have run the server then it show this error, but it still run.

Here is my code in the API, I scared it have problem with async/await so I used .Result

[HttpGet("booking-preview/{bookingId}")]
public IActionResult GetBookingPreview(long bookingId)
{
	if (!ModelState.IsValid)
		return Ok(ModelState);

	var doc = new HtmlToPdfDocument()
	{
		GlobalSettings = {
			PaperSize = PaperKind.A3,
			Orientation = Orientation.Landscape,
		},

		Objects = {
			new ObjectSettings()
			{
				Page = "http://google.com/",
			},
			new ObjectSettings()
			{
				Page = "https://github.com/",

			}
		}
	};
	byte[] pdf = _converter.Convert(doc);
	return new FileContentResult(pdf, "application/pdf");
}

But after have called the API and then return the pdf file, I opened it by browser withBlob or using Pdf reader but it appeared blank/ not support.

Thanks.

[rdvojmoc]

Error that you marked shouldn’t have any impact on conversion process. Can you write PDF to disk on a server to confirm that there is something wrong with the library?

[HttpGet("booking-preview/{bookingId}")]
public IActionResult GetBookingPreview(long bookingId)
{
	if (!ModelState.IsValid)
		return Ok(ModelState);

	var doc = new HtmlToPdfDocument()
	{
		GlobalSettings = {
			PaperSize = PaperKind.A3,
			Orientation = Orientation.Landscape,
		},

		Objects = {
			new ObjectSettings()
			{
				Page = "http://google.com/",
			},
			new ObjectSettings()
			{
				Page = "https://github.com/",

			}
		}
	};
	byte[] pdf = _converter.Convert(doc);
       //this writes pdf to disk
        using (FileStream stream = new FileStream(@"Files\" + DateTime.UtcNow.Ticks.ToString() + ".pdf", FileMode.Create))
        {
                stream.Write(pdf, 0, pdf.Length);
         }
	return new FileContentResult(pdf, "application/pdf");
}

[rdvojmoc]

Can you paste this to your browser URL box: <insert your web server address>/booking-preview/12

This will return file stream directly from your server.