The error seen in attached screenshot appears while any edit window is open on Wikimedia Commons. It disappears after a few seconds but reappears once typing resumes. I have not encountered the error on any other project.
{F31647245}
```
t mw.ime.getIMELanguageList URL1:1:1478
at mw.ime.addIme URL1:5:592
at mw.ime.handleFocus URL1:5:499
at mw.ime.setup/< URL1:5:44
at dispatch URL2:193:742
at add/elemData.handle URL2:190:388
at trigger URL2:239:596
at simulate URL2:240:460
at handler URL2:240:843
URL1: https://meta.wikimedia.org/w/load.php?lang=en&modules=ext.uls.i18n%2Cime%2Clanguagenames%2Cmediawiki%2Cmessages%7Cjquery.i18n%2Cime%2Culs%7Cjquery.uls.grid&skin=vector&version=1n1zi
URL2: https://meta.wikimedia.org/w/load.php?lang=en&modules=ext.TemplateWizard%2Ccharinsert%2CeventLogging%2CnavigationTiming%2CwikimediaEvents%7Cext.TwoColConflict.JSCheck%7Cext.centralNotice.geoIP%7Cext.centralauth.ForeignApi%7Cext.centralauth.centralautologin.clearcookie%7Cext.echo.api%2Cinit%7Cext.uls.common%2Ccompactlinks%2Cinit%2Cinterface%2Cpreferences%2Cwebfonts%7Cjquery%2Cmoment%2Coojs%2Coojs-ui-core%2Coojs-ui-toolbars%2Coojs-ui-widgets%2Coojs-ui-windows%2Csite%7Cjquery.client%2Ccookie%2ClengthLimit%2CmakeCollapsible%2CtextSelection%7Cjquery.makeCollapsible.styles%7Cjquery.uls.data%7Cmediawiki.ForeignApi%2CString%2CTitle%2CUri%2Capi%2Cbase%2Ccldr%2Ccookie%2Cexperiments%2Cicon%2CjqueryMsg%2Clanguage%2Cstorage%2Cuser%2Cutil%2Cwidgets%7Cmediawiki.ForeignApi.core%7Cmediawiki.action.edit%7Cmediawiki.action.edit.collapsibleFooter%7Cmediawiki.libs.pluralruleparser%7Cmediawiki.page.ready%7Cmediawiki.page.watch.ajax%7Cmediawiki.ui.button%7Cmediawiki.widgets.DateInputWidget%2CUserInputWidget%2CvisibleLengthLimit%7Cmediawiki.widgets.DateInputWidget.styles%7Coojs-ui-toolbars.icons%7Coojs-ui-widgets.icons%7Coojs-ui-windows.icons%7Coojs-ui.styles.icons-content%2Cicons-interactions%2Cicons-movement%7Cskins.vector.legacy.js%7Cuser.defaults&skin=vector&version=kj8an
```
== Steps to reproduce
# Enable input methods
# Execute this on console: `$.ime.preferences.registry.previousLanguages = '["en"]'`
# Activate an input field
This corrupted value can be persisted by now opening ULS input preferences, doing a change and saving. The proposed patch will ignore corrupted values on load.
== Expected outcome
Corrupted input method preference values will not prevent input methods from working and log spam is gone.