Error message 'The filename, directory name, or volume label syntax is incorrect'

I am new to nodebox so apologies in advance if this is a stupid question.

I am going through the following step by step to try and create an ellipse shaped data visualisation similar to the 'earthquake' example:
https://www.nodebox.net/node/documentation/using/data-visualization.html

The data I am using has two columns, one with a list of country names and the second with an associated population number.

I can generate everything associated to the first lookup, which gives me a ring of country names. However, whenever I try to generate the second lookup and use the combine node, I keep getting the same error:

• The filename, directory name, or volume label syntax is incorrect -

One time I did actually manage to generate the image I needed, but as soon as I tried to change the font afterwards the same error returned. I don't really understand why the imported file works for the first lookup but not the second. I have double checked and there are no random punctuation marks/symbols etc in the CSV file.

Does anyone know how/why this is happening, and how to fix it?

Thanks for any help/advice!

That does seem strange. I've never seen that error and don't see why it would be triggered only after a second lookup was done.

I am not a staff member but will try to help if I can. Could you respond to this thread and attach a zip file containing your network and csv file so I can try to recreate the error?

Thanks,

John