With the release of Visual Studio 2019, Microsoft have taken the opportunity to clean their front-and-centre Visual Studio website of links to older versions. However, GameMaker Studio 1.4 and GameMaker require older versions of VS for module compatibility. So, how to get the older versions now?
Well, Microsoft do now have a handy page dedicated to downloading older Visual Studio products. The site says you will need to create a Visual Studio Dev Essentials account if you don't have one already. This is free and only takes a few seconds to complete, so isn't much of a disruption.
Scroll down the page a little (if required) until you see the join button.
Sign in using your Microsoft Account (the same one you log into Windows with).
Then fill in the few details Microsoft require in the enrolment form:
Then your account will be created and you will be logged-in automatically.
After this there should be a link saying "Use your benefits" or something to that effect.
Click the Accept button to complete the process:
Once you have accepted, click the Downloads tab at the top of the page, then search for the product you want, and you'll be given a download page result.