Duplicate headers received from server

Question

Duplicate headers received from server

The response from the server contained duplicate headers. This problem is generally the result of a misconfigured

Answer 1

Just put a pair of double quotes around your file name like this:

this.Response.AddHeader("Content-disposition", $"attachment; filename=\"{outputFileName}\"");

Answer 2

The server SHOULD put double quotes around the filename, as mentioned by @cusman and @Touko in their replies.

For example:

Response.AddHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");

Answer 3

For me the issue was about a comma not in the filename but as below: -

Response.ok(streamingOutput,MediaType.APPLICATION_OCTET_STREAM_TYPE).header("content-disposition", "attachment, filename=your_file_name").build();

I accidentally put a comma after attachment. Got it resolved by replacing comma with a semicolon.

Answer 4

This ones a little old but was high in the google ranking so I thought I would throw in the answer I found from Chrome, pdf display, Duplicate headers received from the server

Basically my problem also was that the filename contained commas. Do a replace on commas to remove them and you should be fine. My function to make a valid filename is below.

    public static string MakeValidFileName(string name)
    {
        string invalidChars = Regex.Escape(new string(System.IO.Path.GetInvalidFileNameChars()));
        string invalidReStr = string.Format(@"[{0}]+", invalidChars);
        string replace = Regex.Replace(name, invalidReStr, "_").Replace(";", "").Replace(",", "");
        return replace;
    }

Answer 5

Double quotes around the filename in the header is the standard per MDN web docs. Omitting the quotes creates multiple opportunities for problems arising from characters in the filename.