export local doesn't work, on website it will

After a few years I installed Xerte again to start building. I have created a local page and want to export it to import onto my website. After exporting, the test file (xxx_deploymentTEST.zip) appears to be empty. Other pages also seem to be exported, I don't get any error messages or anything like that, but the export zips are empty. Even after a new installation, the export produces an empty file.
But the installation on my website does make good exports.
Does anyone have an idea what could be going on and how to solve the problem?

So, just to be clear, this is on a local XAMPP install?

Hi Tom,
It is a local XAMPP installation.
gr
Ronald

If you navigate to your XAMPP install's phpinfo.php page, do you see the zip extension?

http://localhost/dashboard/phpinfo.php

In http://localhost/dashboard/phpinfo.php I'm missing the ZIP part.

In your xampp folder go into the php folder and open the php.ini file.

Find the line ';extension=zip' and remove the ';'before that line. Save the file and restart apache and check whther the zip extension is enabled (in phpinfo).