In the Essential theme the grading_navigation.mustache template (from /mod/assign/templates) was copied and slightly changed. Recent changes to the plugins database means that checks are being undertaken, e.g: https://moodle.org/plugins/pluginversion.php?id=13372&smurf=html#mustache with the error "HTML Validation error, line 24: Stray end tag “span”. (v><br/></span></div)".
This has showed up a stray end tag in grading_navigation.mustache line 77 in the M3.1 version and line 74 in the M3.2 version being around here:
Inspection of the full grading page (e.g 'https://moodlesite.mine/mod/assign/view.php?id=55&action=grader') reveals no start 'span' tag when the templates are combined.
Therefore, two things:
- It needs to be removed.
- Automated checks need to be updated to catch this sort of thing on core code as well as contributed code.