Not sure what that error message means, but I would suggest printing the possible paths you are trying to save to and check if there are some forbidden character you are trying use as the file name:
Names Default To Here(1);
dt = Open("$SAMPLE_DATA/big class.jmp");
path1 = "$TEMP/" || Char( dt << get name )||"_"||MDYHMS( Today() )||".jmp";
path2 = "$TEMP/" || Char(dt << get name) || "_" || Format Date(Today(), "ddmonyyyy h:m") || ".jmp";
Show(path1, path2);
For windows:
![jthi_0-1630910170421.png jthi_0-1630910170421.png](https://community.jmp.com/t5/image/serverpage/image-id/35544i88FFBB2D95B64520/image-size/medium?v=v2&px=400)
-Jarmo