Hello,
I could reproduce the issue you reported on a fresh instance. Problem for me was that fs-portlet was declaring to pass a root folder to the underlying folder-chunk file-storage template, but this variable was not set.
Please apply changes in http://cvs.openacs.org/changelog/OpenACS?cs=MAIN%3Aantoniop%3A20180108095458 and http://cvs.openacs.org/changelog/OpenACS?cs=MAIN%3Aantoniop%3A20180108095756 and let me know if this fixes the issue (it did for me).
Also, please let me know which branch of the code you are running on, in a way we can better consider a backport of this change to released 5-9 branch
Thanks and all the best
Antonio
