OP: https://community.xibo.org.uk/t/pdfs-not-displaying-clean-install-cms-4-0-2-docker-windows-player-v4-r400/30016

The fix for this issue requires the layout to be drafted/published so that the widget cache is cleared.

Alternatively you may manually delete the widget cache from the CMS library folder. shared/cms/library/widget/*.html. If you know the widgetId you can delete just that file, or if not you can delete all html files in that folder.