Missing Widget > after WordPress updated from 4.9 to 5.2

Hi guys,

Updated WP from 4.9.10 to 5.2.2.

Edit Page would no longer work – so updated SiteOrigin 2.8.2 to the latest version 2.10.7.

Now when I’m editing a page, it says all my widgets are missing.

Instead of the Widget Name and widget title, it just says the Widget missing and also gives me the namespace of the widget. Example namespace is ThemenameThemeWidgetsHero Image Widget (Widgets in theme.)

I can still edit the widgets, but the data is not saved back to the database.

Is there something different I should have done?

Thanks,
Terry.