Hi,
I think that it's really a cache issue, I can't reproduce the problem on my end.
On your website, when you go in the Joomla global configuration, you can find a message like that:
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JCacheStorage._apc' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/cache/cache.php on line 143
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JCacheStorage._eaccelerator' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/cache/cache.php on line 143
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JCacheStorage._file' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/cache/cache.php on line 143
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JCacheStorage._memcache' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/cache/cache.php on line 143
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JCacheStorage._xcache' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/cache/cache.php on line 143
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JSessionStorage._apc' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/session/session.php on line 283
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JSessionStorage._database' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/session/session.php on line 283
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JSessionStorage._eaccelerator' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/session/session.php on line 283
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JSessionStorage._memcache' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/session/session.php on line 283
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JSessionStorage._none' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/session/session.php on line 283
Mac OS X 2��ATTR��Q�Qcom.apple.quarantineq/0001;4ffb49c2;Safari.app;60D9820D-0154-4312-8D7D-28FBD1299E6B|com.apple.Safari
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'JSessionStorage._xcache' not found in /var/www/vhosts/preview.sermig.org/httpdocs/libraries/joomla/session/session.php on line 283
I don't really know from which component / plugin it can come.