Change 1012726 had a related patch set uploaded (by Cmelo; author: Cmelo):

[mediawiki/extensions/CampaignEvents@master] Add error message in case a user tries to send emails to participants on another wiki

https://gerrit.wikimedia.org/r/1012726

Moved to in review after team discussion on how we will unblock this work, which is: Remove open/close in all cases (whether on the local or foreign wiki) from the kebab menu, and redirect users to special delete page if on a foreign wiki

Change #1012726 merged by jenkins-bot:

[mediawiki/extensions/CampaignEvents@master] EmailUsersHandler: fail if the event is not local

https://gerrit.wikimedia.org/r/1012726

Given a user tries to email participants using the "Email participants" API endpoint
And the event does not belong to the current wiki
✅ Then they should receive a 4xx response with an error message similar to that used in T358781

In T359491#9705401, @vaughnwalters wrote:

Given a user tries to email participants using the "Email participants" API endpoint
And the event does not belong to the current wiki
✅ Then they should receive a 4xx response with an error message similar to that used in T358781

❌ And this new error should be documented on mediawiki.org
@cmelo The error message Please email participants on XXX, the wiki where the event was created. needs to be added to the Email participants documentation on mediawiki.org

✅ Error message is now documented on mediawiki.org

Sending to product sign off

@vaughnwalters

❌ And this new error should be documented on mediawiki.org
@cmelo The error message Please email participants on XXX, the wiki where the event was created. needs to be added to the [[

Done, thank you!