This command WORKS (creates a PDF with the "Arial" font):

    pandoc --pdf-engine=xelatex -V pagestyle="empty" -V mainfont="Arial" -V monofont="Arial" -V fontsize=10pt --verbose -V papersize="A4" -V margin-top="2cm" -V margin-right="2cm" -V margin-bottom="2cm" -V margin-left="2cm" "test.md" -o "out.pdf"

This command also WORKS (creates a PDF with the "Courier New" font):

    pandoc --pdf-engine=xelatex -V pagestyle="empty" -V mainfont="Courier New" -V monofont="Courier New" -V fontsize=10pt --verbose -V papersize="A4" -V margin-top="2cm" -V margin-right="2cm" -V margin-bottom="2cm" -V margin-left="2cm" "test.md" -o "out.pdf"

However, both these commands FAIL (no PDF created at all):

    pandoc --pdf-engine=xelatex -V pagestyle="empty" -V mainfont="Courier" -V monofont="Courier" -V fontsize=10pt --verbose -V papersize="A4" -V margin-top="2cm" -V margin-right="2cm" -V margin-bottom="2cm" -V margin-left="2cm" "test.md" -o "out.pdf"

    pandoc --pdf-engine=xelatex -V pagestyle="empty" -V mainfont="Courier Standard" -V monofont="Courier Standard" -V fontsize=10pt --verbose -V papersize="A4" -V margin-top="2cm" -V margin-right="2cm" -V margin-bottom="2cm" -V margin-left="2cm" "test.md" -o "out.pdf"

From the massive dump of output (containing lots of private paths and stuff), I was able to extract out these clues:

    xdvipdfmx:fatal: This font using the "seac" command for accented characters...

    No output PDF file written.

What does it mean? What exactly is wrong? In Windows' font dir, there is a "Courier Standard", which, when opened, is simply called "Courier". Both of those strings result in the nonsensical error.

Pandoc version: 2.9.1.1