MSVC2019 Build From CMD line: VCVARS32.BAT: "Common was unexpected at this time."


I am trying to build an app from the CMD line using MSVC 2019.
The instructions that came with the project (libssl) say to run "VCVARS32.BAT" and then "nmake".
When I run VCVARS32.BAT, the following error message is emitted:

Common was unexpected at this time  

A similar issue was discussed in SO (#8756828) but that one applied to modifying VCVARS32 which I am not doing. An answer to that also mentioned quote marks within the PATH, but I checked and that is not so.

I am running from a base CMD.EXE prompt on a Dell Win10-64 machine.

Any idea why this is happening?

Source: Visual Studio Questions