The 'image column writer' node does not gracefully handle folder separator characters in the row ID, instead it goes looking for a subfolder in v2.8.0. Whilst this could be desired for large collections of images to save, it would also be nice if the node completed execution when the folder did not exist.
It was not intended to be used like that, but the simplest path forward was to support directory creation so now it will create the folders as needed.
It wasn't intentional I promise ;-) I am working on some onekp.com data and the taxomic clade for each sample just happened to include a slash character....
On another matter, is there a reason why the Excel writer node no longer permits collection columns to be saved to Excel?