Some global preferences can not be given local exceptions, even though they appear to in the interface. Examples include "Image size limit on file description pages", "Enable Media Viewer", "Do not show page content below diffs", and seemingly everything beneath the "Time offset" section.
List of steps to reproduce (step by step, including full links if applicable):
- Go to Special:GlobalPreferences > Appearance and make sure "Enable Media Viewer" is set, and save if necessary.
- Go to Special:Preferences and select "Set a local exception for this global preference" beneath the "Enable Media Viewer" option.
- The "Enable Media Viewer" checkbox is disabled
What should have happened instead?:
- The "Enable Media Viewer" should be enabled, allowing me to make a local exception for the global preference.
Software version: MW 1.38.0-wmf.9