Exporting presets - .xmp file not saving text

I am trying to save two presets (one color and one black and white preset) to include in a course that I am teaching.  It is my understanding that I will need to share the .xmp files with my students, correct?  The issue that I am having is that the .xmp file for the color preset is blank with no text whatsoever.  The black and white preset appears to be copying just fine.  I have tried to remake the color preset and rename the preset multiple times, but nothing seems to be saving the text to the .xmp file.  Any idea why this would be happening?  Thanks in advance for your help.