A banner presumably began sampling at much higher frequency leading to a spike in this error in the last 2 days on German Wikipedia
at trigger URL1:261:643 at trigger/< URL1:262:572 at each URL1:151:2 at each URL1:149:2 at trigger URL1:262:543 at r</</h.dispatchEvent URL2:6:61738 at dispatchScrollEvent URL2:26:4046 at positionSlider URL2:26:3726 at positionSliderAtSelected URL2:26:4194 at r</</h.select URL2:6:61996 at r</</h.selectInitialIndex URL2:6:63305 at r</</h.activate URL2:6:57948 at r</</h._create URL2:6:57406 at p URL2:6:56543 at value URL2:16:2394 at value URL2:31:80383 at I/</< URL2:1:7724 at I/< URL2:1:7704 at I URL2:1:7663 at P URL2:1:9773 at value URL2:6:96934 at URL2:31:95571 at n URL2:1:110 at URL2:1:902 at URL2:1:913 at DOMEval URL1:148:287 at domManip URL1:225:311 at prepend URL1:227:585 at injectBannerHTML URL1:8:141 at reallyInsertBanner URL1:12:271 at insertBanner/< URL1:14:288 at mightThrow URL1:195:149 at resolve/</process< URL1:195:808 URL1: https://de.wikipedia.org/w/load.php?lang=de&modules=ext.centralNotice.choiceData%2Cdisplay%2CgeoIP%2CimpressionDiet%2CkvStore%2ClegacySupport%2CstartUp%7Cext.centralauth.centralautologin%7Cext.cite.ux-enhancements%7Cext.cx.eventlogging.campaigns%7Cext.eventLogging%2CnavigationTiming%2Cpopups%2CwikimediaEvents%7Cext.flaggedRevs.advanced%7Cext.quicksurveys.init%2Clib%7Cext.uls.common%2Ccompactlinks%2Cinterface%2Cpreferences%2Cwebfonts%7Cjquery%2Coojs%2Coojs-router%2Coojs-ui-core%2Coojs-ui-widgets%2Csite%7Cjquery.client%2Ccookie%2CtextSelection%7Cjquery.uls.data%7Cmediawiki.String%2CTitle%2CUri%2Capi%2Cbase%2Ccldr%2Ccookie%2Cexperiments%2CjqueryMsg%2Clanguage%2Cstorage%2Ctoc%2Cuser%2Cutil%2Cviewport%7Cmediawiki.editfont.styles%7Cmediawiki.libs.pluralruleparser%7Cmediawiki.page.ready%7Cmediawiki.ui.button%2Cicon%7Cmmv.bootstrap%2Chead%7Cmmv.bootstrap.autostart%7Coojs-ui-widgets.icons%7Cskins.vector.legacy.js%7Cuser.defaults&skin=vector&version=hjcs8 URL2: https://de.wikipedia.org/wiki/Karl_Ove_Knausg%C3%A5rd line 148 > injectedScript