Allegedly, on or about 30 May 2018, Samuel Sieb sent:
However, it seems the problem is with Chrome. I know with Firefox you can set whether to just save or else open an application with a downloaded file, but I don't know where that would be set with Chrome.
One thing to check is whether it's all such links, or just from one website. If a website is providing links with the wrong MIME type headers, that's going to confuse things, no end.