Example reproduction: https://www.wikidata.org/wiki/Special:ItemByTitle/idwiki/asisten_dosen
Logstash link: https://logstash.wikimedia.org/goto/d48663cacfbcb0bc5d8eb2ed03412eee
This is new in .25 it would seem.
[WqsDxgpAICsAABX9yU4AAAAJ] /wiki/Special:ItemByTitle/idwiki/asisten_dosen Wikimedia\Assert\ParameterTypeException from line 89 of /srv/mediawiki/php-1.31.0-wmf.25/vendor/wikimedia/assert/src/Assert.php: Bad value for parameter $pageTitle: must be a string
#0 /srv/mediawiki/php-1.31.0-wmf.25/extensions/Wikibase/lib/includes/Store/Sql/SiteLinkTable.php(216): Wikimedia\Assert\Assert::parameterType(string, boolean, string)
#1 /srv/mediawiki/php-1.31.0-wmf.25/extensions/Wikibase/repo/includes/Specials/SpecialItemByTitle.php(125): Wikibase\Lib\Store\Sql\SiteLinkTable->getItemIdForLink(string, boolean)
#2 /srv/mediawiki/php-1.31.0-wmf.25/includes/specialpage/SpecialPage.php(522): Wikibase\Repo\Specials\SpecialItemByTitle->execute(string)
#3 /srv/mediawiki/php-1.31.0-wmf.25/includes/specialpage/SpecialPageFactory.php(579): SpecialPage->run(string)
#4 /srv/mediawiki/php-1.31.0-wmf.25/includes/MediaWiki.php(288): SpecialPageFactory::executePath(Title, RequestContext)
#5 /srv/mediawiki/php-1.31.0-wmf.25/includes/MediaWiki.php(861): MediaWiki->performRequest()
#6 /srv/mediawiki/php-1.31.0-wmf.25/includes/MediaWiki.php(524): MediaWiki->main()
#7 /srv/mediawiki/php-1.31.0-wmf.25/index.php(42): MediaWiki->run()
#8 /srv/mediawiki/w/index.php(3): include(string)
#9 {main}