Latest versions of Microsoft Visio no longer support VSD format and thus it's not that easy to produce .vsd files from the newer .vsdx files.
If you own the 2010 version of Microsoft Visio, you will need to download the Microsoft Visio Compatibility Pack from Microsoft Website, which adds support for the new VSDX file format. For this you need to have the 2010 version updated and Microsoft Visio 2013 Viewer may also need to be installed in your system as it shares some functions with the compatibility pack.
Microsoft Visio is not available for Mac, but there are some vsdx & vsd viewers available that may allow users to transform various Visio formats. A good alternative to Visio seems to be ConceptDraw Pro diagramming software which is available for both Windows and macOS users.