Same issue for me, tried suggested procedure with the push button, and get this in the /var/udx/logs/log
Updating FreeBSD repository catalogue...
FreeBSD repository is up to date.
Updating FreeBSD-base repository catalogue...
FreeBSD-base repository is up to date.
Updating udi repository catalogue...
Fetching meta.conf: . done
Fetching packagesite.pkg: ... done
pkg: -----BEGIN PUBLIC KEY-----
.....
-----END PUBLIC KEY-----
: rsa signature verification failure
pkg: Invalid signature, removing repository.
Unable to update repository udi
Error updating repositories!