In the future, I recommend you attach pictures as pictures, ideally in the PNG format (use MSPaint to convert to PNG). The file size will be smaller, and we don't have to open each file in Word just to see the picture. Moreover, Word files are potentially dangerous since they can contain macros etc, so in general I would be very suspicious against someone sending me pictures in Word format...
Although the whole error message cannot be seen, my guess (tell me if I'm wrong, and if so let me know all the steps you do, leading up to the error message!) is that you have imported an XYZ file from the directory "F:\diamond nanostructures...". Either this XYZ file does not have any "name" inside it (second row in the file), or the name is "F:\diamond nanostructures...".
This name contains illegal file name characters (":") and will not work. I agree it's a bug, of sorts; VNL should probably filter out such characters, but to overcome it I suggest you either fix the name in the XYZ file (either change it or add it, if it's missing), or copy the Python code from the "Result Browser" to the "Script Editor" and drop the molecule from there, in order to "lose" the file name.
