MediaWiki version: 1.35.0-wmf.15
PHP Warning: Invalid argument supplied for foreach()
There's a few of these after I promoted 1.35.0-wmf.15 to all wikis half an hour ago. Not enough to warrant rollback, I think. Superficially, this looks similar to https://phabricator.wikimedia.org/T242856 which was fixed and backported yesterday, so adding Lucas as subscriber in case it's actually related.
https://logstash.wikimedia.org/goto/fe3b35077b0d42e7fcb13df47a4c2f6f for an example in logstash, for those who have access.