"Lastest moodle instlalation package" – Can you tell us more precisely? You may have 3.10 (the latest release), or 3.11 or 4.0 which are both development versions.
"Xampp 3.2.4" – are you sure? The current version is 7.2.34.
Can you find out which version of PHP your Xampp has? This may show up in the php.exe's file properties in Microsoft Windows, or run php --version at the command line. I suspect it's PHP 8.0 as this has a change listed which could cause this error:
Fixed bug #79521 (Check __set_state structure).
Moodle doesn't support PHP 8.0, for Moodle 3.10:
PHP version: minimum PHP 7.2.0 Note: minimum PHP version has increased since Moodle 3.8. PHP 7.3.x and 7.4.x are supported too.
So if you do have PHP 8.0 you'll need to swtich to a Xampp version with an one of the above listed versions instead.