If you’re running Kororaa Beta2, there are a few bugs which require fixing.
Firstly, the KDE version incorrectly included Yum from Rawhide (development) tree (GNOME version does not have this issue). This means you are running an untested version of Yum, the system’s default package manager.
To fix this, disable the repo (or remove the repository file for it), then downgrade yum to the stable version. sudo sed -i 's/enabled=1/enabled=0/g' /etc/yum.repos.d/fedora-yum-rawhide.repo
sudo yum downgrade yum
The Livna repository, which is configured out of the box, seems to be having lots of problems with availability. This will be fixed in the next release, but in the mean time, you can disable or remove that repository. sudo sed -i 's/enabled=1/enabled=0/g' /etc/yum.repos.d/livna.repo