We are getting an error when a
group_content_menu →
is in a workspace.
Symfony\Component\Routing\Exception\MissingMandatoryParametersException: Some mandatory parameters are missing ("group") to generate a URL for route "entity.group_content_menu.workspace.revisions_diff". in Drupal\Core\Routing\UrlGenerator->doGenerate() (line 187 of core/lib/Drupal/Core/Routing/UrlGenerator.php).
Add a group_content_menu item to a workspace with the diff module enabled and goto the Manage Workspace page.
Extend the entity.$entity_type_id.workspace.revisions_diff route and link generator to support multiple entities. I'm not sure this is possible to support here? Maybe group_content_menu needs to support this since there may not be a way to discern the group parameter in a generic way.
Needs work
2.0
Code
GroupContentMenu::urlRouteParameters is what should be providing the route. There is probably a more foolproof method to get the group and all these parameters from the URL.
Alternatively, we could do a try/catch around the URL generation to catch these types of things in a more generic manner.