[ovirt-users] Yum error while installing host on Centos7

I installed ovirt-engine on Centos7. My target is to have a single host machine. During the installation of the (first and unique) host, I get an error: Failed to install Host xxxx. Yum Non-fatal POSTIN scriptlet failure in rpm package gtk2-2.24.28-8.el7.x86_64. This error is followed by other errors: Failed to install Host xxxx. Failed to execute stage 'Package installation': One or more elements within Yum transaction failed. and finally: Host xxxx installation failed. Command returned failure code 1 during SSH session 'root(a)xxxx.mydomain.it'. All other libraries are yum-installed without problems.