from https://www.mozilla.org/firefox/98.0.1/releasenotes/ <blockquote>Yandex and Mail.ru have been removed as optional search providers in the drop-down search menu in Firefox. If you previously installed a customized version of Firefox with Yandex or Mail.ru, offered through partner distribution channels, this release removes those customizations, including add-ons and default bookmarks. Where applicable, your browser will revert back to default settings, as offered by Mozilla. All other releases of Firefox remain unaffected by the change.</blockquote> Yandex and Mail.ru have been removed as optional search providers in the drop-down search menu in Firefox. You can update and/or add search engines at any time in Settings. Click the Menu button, select Settings and click Search. You can also add Yandex search if you go to Yandex site and add it to search bar or you can go to https://mycroftproject.com/search-engines.html?name=Yandex https://support.mozilla.org/en-US/kb/search-engine-removal https://support.mozilla.org/en-US/kb/add-or-remove-search-engine-firefox