Admin > Extras > Translationsand check if you have at least one translation in place.
Admin > Extras > Translationsand check if at least one transaction is marked as default. (Click on the CheckMark button on a translation to mark it as a default translation)
Admin > Settings > Push Notifications > Firebase Web Push Certificateand check whether you have removed the FIrebase Web Push Certificate. Even if you do not intent to use Firebase push notifications, this field is not meant to be removed. If you have removed it by mistake, insert the following, and save your settings.
Admin > Settings > Cache Settings > Force Clear Cache
Admin > Settings > Fix Update Issues