Hi 
I found the problem
If you are using RHEL/CentOS 7, edit /etc/yum.repos.d/kaltura.repo and change the [Kaltura] section:
baseurl = http://installrepo.kaltura.org/releases/latest/RPMS/$basearch/
to read:
baseurl = http://installrepo.kaltura.org/releases/rhel7/RPMS/$basearch/
Best Regards,