No valid values found on filter

Problem/Motivation

Hi, sorry for my bad english.

I need a view that filters media based on a fixed directory, but when I add the filter to the view I get an invalid value error on the filter (which doesn't happen if I expose the filter)

Steps to reproduce

- I have a hierarchical taxonomy configured as directory structure on /admin/config/media/media_directories
- I create a view that list medias as rendered entity
- I add a "Media directory filter" and select a single taxonomy term of the taxonomy (in this case a leaf)
- on saving I get the error in question and the filter shows (= unknown)

Proposed resolution

In the next comment a proposed patch