Admin > Extras > Translations and check if you have at least one translation in place.
Admin > Extras > Translations and 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 Certificate and 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.
Then go to
Admin > Settings > Cache Settings > Force Clear Cache
If you use a www version of your website during the installation, you might face this issue.
Make sure you always use a non-www version of the URL.
Admin > Settings > Fix Update Issues