Recently when trying to server up some images that were stored in an Azure storage container, we were noticing that the files presented this error message when using Chrome (but Fiddler traces showed success and it worked fine in other browsers).

It turns out this was not caused by duplicate header values being added to the response but instead it was because the image file name contained a comma that was not properly escaped by putting double quotes around the filename like this:

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