Редактор перестал понимать формат даты на РИА Новости:
{{Cite news|title=Во Франции обнародовали документ о публичной деятельности Брижит Макрон|url=https://ria.ru/world/20170821/1500769149.html|work=РИА Новости|date=20170821T1415+0300Z|accessdate=2017-10-18|language=ru}}
Assuming no recent changes to the Cite news template on that wiki: in the source code of the article, there's this <meta property="article:published_time" content="20170821T1415+0300Z"> tag that seems to be where the date is taken from. Did the site really use a different format before? I tried with a news article from 6 years ago and it didn't make a difference, maybe they switched everything so that it now follows an ISO 8601 standard? Ping @User:Mvolz (WMF). (On en.wiki, while creating the reference we get an error message and are redirected to https://en.wikipedia.org/wiki/Help:CS1_errors#bad_date instead.)
Could it be changed somwhere so the date= will receive YYYY-MM-DD?
This is not the only site, so conversion YYYYMMDDTHHMMtimezone to YYYY-MM-DD should be implemented.
In the template: Citoid/Enabling_Citoid_on_your_wiki#Access_date_is_formatted_differently_on_my_wiki.
We did previously validate dates more strongly, but there were issues related to that, and then relaxed validation. So it's possible this was due to https://phabricator.wikimedia.org/T132308
We should be able to convert this date, so I am not sure why it is not working. I will look into it.
Thank you for reporting!
I have created a new task to track this here: https://phabricator.wikimedia.org/T178586
