NXP-25021 was supposed to bring a better handling of an expired session in the Web UI by displaying a banner offering a link to the login page. This behavior does not appear even after installing HF13, the VIEW page still shows a 404 error message when navigating to another document and no banner appears. The reproduction scenario from NXP-25021 still stands.
This was tested with 9.10-H-21 ( and also 10.2 but fixed in 10.3-SNAPSHOT).
Please note that the banner with the link to the login page appears on http://nightly.nuxeo.com/ (10.3-dated).