==== Error ====
* mwversion: `1.37.0-wmf.4`
* reqId: `e862260d-3cf7-413f-be6f-3916a996efbf`
* [[ https://logstash.wikimedia.org/app/dashboards#/view/AXFV7JE83bOlOASGccsT?_g=(time:(from:'2021-05-04T13:41:28.000Z',to:'2021-05-05T13:42:44.423Z'))&_a=(query:(query_string:(query:'reqId:%22e862260d-3cf7-413f-be6f-3916a996efbf%22'))) | Find reqId in Logstash ]]
* [[ https://logstash.wikimedia.org/app/dashboards#/view/AXFV7JE83bOlOASGccsT?_g=(time:(from:now-30d,to:now))&_a=(query:(query_string:(query:'normalized_message:%22%5B%7BreqId%7D%5D%20%7Bexception_url%7D%20%20%20Wikimedia%5CRdbms%5CDBQueryError:%20Error%201054:%20Unknown%20column%20'actor_user'%20in%20'on%20clause'%20(10.64.16.208)%0AFunction:%20SpecialRecentChanges::doMainQuery%0AQuery:%20SELECT%20%20rc_id,rc_timestamp,rc_namespace,rc_title,rc_minor,rc_bot,rc_new,rc_c%22'))) | Find normalized_message in Logstash ]]
```name=normalized_message
[{reqId}] {exception_url} Wikimedia\Rdbms\DBQueryError: Error 1054: Unknown column 'actor_user' in 'on clause' (10.64.16.208)
Function: SpecialRecentChanges::doMainQuery
Query: SELECT rc_id,rc_timestamp,rc_namespace,rc_title,rc_minor,rc_bot,rc_new,rc_c
```
```name=exception.trace,lines=10
from /srv/mediawiki/php-1.37.0-wmf.4/includes/libs/rdbms/database/Database.php(1738)
#0 /srv/mediawiki/php-1.37.0-wmf.4/includes/libs/rdbms/database/Database.php(1722): Wikimedia\Rdbms\Database->getQueryException(string, integer, string, string)
#1 /srv/mediawiki/php-1.37.0-wmf.4/includes/libs/rdbms/database/Database.php(1697): Wikimedia\Rdbms\Database->getQueryExceptionAndLog(string, integer, string, string)
#2 /srv/mediawiki/php-1.37.0-wmf.4/includes/libs/rdbms/database/Database.php(1260): Wikimedia\Rdbms\Database->reportQueryError(string, integer, string, string, boolean)
#3 /srv/mediawiki/php-1.37.0-wmf.4/includes/libs/rdbms/database/Database.php(1948): Wikimedia\Rdbms\Database->query(string, string, integer)
#4 /srv/mediawiki/php-1.37.0-wmf.4/includes/libs/rdbms/database/DBConnRef.php(68): Wikimedia\Rdbms\Database->select(array, array, array, string, array, array)
#5 /srv/mediawiki/php-1.37.0-wmf.4/includes/libs/rdbms/database/DBConnRef.php(313): Wikimedia\Rdbms\DBConnRef->__call(string, array)
#6 /srv/mediawiki/php-1.37.0-wmf.4/includes/specials/SpecialRecentChanges.php(413): Wikimedia\Rdbms\DBConnRef->select(array, array, array, string, array, array)
#7 /srv/mediawiki/php-1.37.0-wmf.4/includes/specialpage/ChangesListSpecialPage.php(1032): SpecialRecentChanges->doMainQuery(array, array, array, array, array, FormOptions)
#8 /srv/mediawiki/php-1.37.0-wmf.4/includes/specialpage/ChangesListSpecialPage.php(635): ChangesListSpecialPage->getRows()
#9 /srv/mediawiki/php-1.37.0-wmf.4/includes/specials/SpecialRecentChanges.php(203): ChangesListSpecialPage->execute(NULL)
#10 /srv/mediawiki/php-1.37.0-wmf.4/includes/specialpage/SpecialPage.php(646): SpecialRecentChanges->execute(NULL)
#11 /srv/mediawiki/php-1.37.0-wmf.4/includes/specialpage/SpecialPageFactory.php(1396): SpecialPage->run(NULL)
#12 /srv/mediawiki/php-1.37.0-wmf.4/includes/MediaWiki.php(313): MediaWiki\SpecialPage\SpecialPageFactory->executePath(string, RequestContext)
#13 /srv/mediawiki/php-1.37.0-wmf.4/includes/MediaWiki.php(916): MediaWiki->performRequest()
#14 /srv/mediawiki/php-1.37.0-wmf.4/includes/MediaWiki.php(550): MediaWiki->main()
#15 /srv/mediawiki/php-1.37.0-wmf.4/index.php(53): MediaWiki->run()
#16 /srv/mediawiki/php-1.37.0-wmf.4/index.php(46): wfIndexMain()
#17 /srv/mediawiki/w/index.php(3): require(string)
#18 {main}
```
==== Impact ====
https://www.mediawiki.org/wiki/Special:RecentChanges?userExpLevel=newcomer is unavailable.
==== Notes ====
This is happening as of today on mediawiki.org