Any chance that can be related to the previous blocker about how wikibase inserts RC records? T172320: Error in Wikibase/client/includes/Changes/InjectRCRecordsJob.php line 120: Bad value for parameter $params: $params['change'] not set.

Is there also a trace in the logs so we know who's calling?

Relevant code (from current version of wmf.12):

https://github.com/wikimedia/mediawiki/blob/8e7900b115/includes/specials/SpecialContributions.php#L132-L204
It seems like the $skip case would naturally have start and end undefined. The code doesn't appear to have changed recently, but perhaps a particular call pattern has become more common with the introduction of ORES and date filters?

In T172438#3498919, @SBisson wrote:

Any chance that can be related to the previous blocker about how wikibase inserts RC records? T172320: Error in Wikibase/client/includes/Changes/InjectRCRecordsJob.php line 120: Bad value for parameter $params: $params['change'] not set.

I don't think so. Special:Contributions doesn't use the recentchanges table.

I don't think this is related to the Collaboration team, or a recent regression, but it's worth fixing. It looks to be from rMWb66888733c18: Use PHP DateInputWidget in Contribs and use for range filtering

Change 370097 had a related patch set uploaded (by Mattflaschen; owner: Mattflaschen):
[mediawiki/core@master] Special:Contribs: Ensure 'start' and 'end' are never undefined

https://gerrit.wikimedia.org/r/370097

Change 370097 merged by jenkins-bot:
[mediawiki/core@master] Special:Contribs: Ensure 'start' and 'end' are never undefined

https://gerrit.wikimedia.org/r/370097

Change 370142 had a related patch set uploaded (by Krinkle; owner: Mattflaschen):
[mediawiki/core@wmf/1.30.0-wmf.12] Special:Contribs: Ensure 'start' and 'end' are never undefined

https://gerrit.wikimedia.org/r/370142

Change 370142 merged by jenkins-bot:
[mediawiki/core@wmf/1.30.0-wmf.12] Special:Contribs: Ensure 'start' and 'end' are never undefined

https://gerrit.wikimedia.org/r/370142