It is difficult to see what is going on. You could try to modify this example and import the CSV files via Readr package which is more tolerant/smart with regards to messy CSV files. Also you should make sure you browse the right folder and there are no strange files.
You column aggregator node suggests there were quite some different columns present before.
And maybe you check if this is the right folder:
C:\Users\xxxxxx\Desktop\New folder (2)
Of course you are free to name your folders like you want but maybe you have a path that is more significant and try to loose too much special characters , blanks and brackets - could be the URLs do not like that, even if they should be able to handle it.