Failed software update of 'Welcome' package - 'Requires installation of untrusted packages' UM 16.04

[wizd3m]

It seems that one of the packages needs a new key. Did you install Virtualbox? Then it is correct you get this error when upgrading (either through Software Updater or manually).

This has already been reported and a fix is on the way.

VirtualBox from Software Boutique Untrusted source error

When trying to install VirtualBox from Software Boutique on fresh 16.04 get an error "Requires installation of untrusted packages" This requires installing packages from unauthenticated sources. I can till get it via App Grid etc without any problems, but it stands out especially when everything in Welcome app is for new users.