Hi @MarkA.Bachman,
I’m guessing that you have copied the X-Carve post into your My_PostP folder? If you do this you will also need to copy the Grbl_mm.pp file to the same location, as the X-Carve post is a mod of the core Grbl one (I’ll see if we can avoid this additional step in a future patch I think). For now though, the grbl_mm.pp file should be included in any standard install and you can get to it from File->Open Application Data Folder… then find and copy the file from the PostP folder into your My_PostP folder alongside the X-Carve one using windows file explorer.
I hope this gets you up and running.
E