I'd like to upgrade to Fedora 27 but currently it doesn't download via console due to the following error:
nss-pem-1.0.3-3.fc26.x86_64 does not belong to a distupgrade repository

Specificially I did make sure everything is up to date with dnf upgrade --refresh and then installed the dnf system upgrade plugin.
Then I ran dnf system-upgrade download --releasever=27 and got the following output:
~ dnf system-upgrade download --releasever=27
Before you continue ensure that your system is fully upgraded by running "dnf --refresh upgrade". Do you want to continue [y/N]: y
Fedora 27 - x86_64 - Updates 1.6 MB/s | 7.4 MB 00:04
Failed to synchronize cache for repo 'region51-chrome-gnome-shell', disabling.
Failed to synchronize cache for repo 'virtualbox', disabling.
Last metadata expiration check: 0:00:00 ago on Di 14 Nov 2017 18:43:21 CET.
Problem: nss-pem-1.0.3-3.fc26.i686 has inferior architecture
- nss-pem-1.0.3-3.fc26.x86_64 does not belong to a distupgrade repository
- problem with installed package nss-pem-1.0.3-3.fc26.i686

Simply removing the package does not work. See:
~ dnf remove nss-pem.i686
Dependencies resolved.
================================================== =============================================
Package Arch Version Repository Size
================================================== =============================================
nss-pem i686 1.0.3-3.fc26 @@commandline 215 k
Removing dependent packages:
libcurl i686 7.53.1-12.fc26 @updates 541 k
libdbusmenu-gtk2 i686 16.04.0-2.fc26 @@commandline 79 k
libdbusmenu-gtk3 i686 16.04.0-2.fc26 @@commandline 79 k
steam i686 @@commandline 2.7 M
Removing unused dependencies:
libXScrnSaver i686 1.2.2-11.fc26 @@commandline 35 k
libatomic i686 7.2.1-2.fc26 @updates 21 k
libdbusmenu i686 16.04.0-2.fc26 @@commandline 531 k
libnghttp2 i686 1.21.1-1.fc26 @@commandline 155 k
libpsl i686 0.18.0-1.fc26 @updates 55 k
libssh2 i686 1.8.0-5.fc26 @updates 197 k
libtxc_dxtn i686 1:1.0.1-2.gitef072983.fc26 @@commandline 19 k
libva-intel-driver i686 1.8.3-2.fc26 @rpmfusion-free-updates 4.2 M

Transaction Summary
================================================== =============================================
Remove 13 Packages

Freed space: 8.7 M
Is this ok [y/N]:

It would remove packages I want to keep.

It does download via Gnome, but I don't trust the Gnome upgrade path. When the console reports an issue before download and Gnome does not even after downloading there needs to be an issue with gnome installer.