Adam

I've also run into this in the context of the Imagemagick `policy.xml`... digging in, it appears to be due to the single-quotes in the `#FIXED ''` bits? Rolled a slight...

I've also run into this, having been using the `drush config-set` command with Drush 8 to create a `filter.format.restricted_html` config_entity in order to work around [an issue in another module](https://www.drupal.org/project/eu_cookie_compliance/issues/2979440),...

Just ran into this, and yeah, keeping Drush back at `11.5.1` seems to do the trick.

I've thrown together #28, that I think should address this.