The file came from an old forum link, buried in a thread titled “Legacy installers – no key needed.” The user “dlmsfx” had posted it three years ago with a single comment: “Hot version – includes last official patch before they changed the licensing model.”
AutoCAD 2021 introduced several "hot" features that improved workflow efficiency: autocad 2021 english win 64bit dlmsfx hot
If you have already installed a “dlmsfx hot” version: The file came from an old forum link,