I assume you use NS 6. There are no new rpms for CentOS6 so I installed it from source and it worked, see Urbackup restore, not work - #7 by mrmarkuz
My installation notes:
service urbackup-server stop
yum -y install http://www.city-fan.org/ftp/contrib/yum-repo/rhel6/i386/city-fan.org-release-2-1.rhel6.noarch.rpm
yum -y --enablerepo=city-fan.org install libcurl-devel cryptopp-devel gcc-c++ zlib-devel
cd ~
wget https://hndl.urbackup.org/Server/2.3.7/urbackup-server-2.3.7.tar.gz
tar xf urbackup-server-2.3.7.tar.gz
cd urbackup-server-2.3.7
./configure
make
make install
urbackupsrv run -d