Hi
are you talking about an IT team?
The php-zip extension doesn't require Xerte specific knowledge it's just a PHP extension that needs to be installed/enabled on the web server for Xerte to be able to function correctly and create the export zips that you have reported are no longer being created.
As I already mentioned something must have been changed if the exports worked previously but don't any longer. That might be change of server, upgrade of server OS and/or components and/or Xerte.
Our list of system requirements is available via
xot.xerte.org.uk/play.php?template_id=81#systemrequirements
and there are both install and upgrade guides in the documentation folder within the download.
But ultimately someone has made a change on your server that has caused the exports to stop working and whoever looks after your server should be able to work out what that was and/or to view the server logs to identify the cause/solution.
If they require free support they can post here.
If they require commercial support with installation and maintenance, upgrades and bespoke developments then some of us provide that including remotely looking after in-house installation to external hosting etc.
HTH
Ron