Adding calendar fails - PHP Fatal error: Class ' Archive_Tar' not found

hi
I run of Centos 7.4 with:
nextcloud-httpd-10.0.4-2.el7.noarch
nextcloud-10.0.4-2.el7.noarch
nextcloud-mysql-10.0.4-2.el7.noarch

Server version: Apache/2.4.6 (CentOS)
Server built: Oct 19 2017 20:39:16
Server’s Module Magic Number: 20120211:24
Server loaded: APR 1.4.8, APR-UTIL 1.5.2
Compiled using: APR 1.4.8, APR-UTIL 1.5.2
Architecture: 64-bit
PHP Version: 5.4.16

When I try to enable “Calendar” app it fails: Error whilst enabling app
in apache log:
[Thu Nov 23 18:00:08.912966 2017] [:error] [pid 959704] [client 172.24.154.138:45272] PHP Fatal error: Class ' Archive_Tar' not found in /usr/share/nextcloud.clustered/lib/private/Archive/TAR.php on line 56
many thanks & regards

Probably some required php modules weren’t installed:
https://docs.nextcloud.com/server/12/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation

(start to check the module zip)