Just after last upgrade, I discover that our roundcubemail is broken for calendar events. We are using Debian 10.
I had kept the older roundcube (1.4.x) up to now, so I thought this might be the cause of the error. So I tried to fix using latest roundcubemail (which install properly only using aptitude), version 1.5.3, but this does not change anything: everything is fine except anything related to calendar (calendars show as empty and emails containing calendar events show 'internal server error').
In /var/log/roundcubemail/errors.log this error is repeated (under either version of roundcube):
[27-Dec-2022 11:30:22 UTC] PHP Fatal error: Uncaught TypeError: No matching function for overloaded 'new_Event' in /usr/share/php/kolabobject.php:171
Stack trace:
#0 /usr/share/php/kolabobject.php(171): Event->__construct(Resource id #50)
#1 /usr/share/roundcubemail/plugins/libkolab/lib/kolab_format.php(498): XMLObject->readEvent('<?xml version="...', 1)
#2 /usr/share/roundcubemail/plugins/libkolab/lib/kolab_storage_folder.php(560): kolab_format->load('<?xml version="...')
#3 /usr/share/roundcubemail/plugins/libkolab/lib/kolab_storage_cache.php(1111): kolab_storage_folder->read_object('978', '*')
#4 /usr/share/roundcubemail/plugins/libkolab/lib/kolab_storage_cache.php(812): kolab_storage_cache->_unserialize(Array)
#5 /usr/share/roundcubemail/plugins/libkolab/lib/kolab_storage_folder.php(302): kolab_storage_cache->select(Array, false, false)
#6 /usr/share/roundcubemail/plugins/calendar/drivers/kolab/kolab_calendar.php(319): kolab_storage_folder->select(Array)
#7 /usr/share/roundcubemail/plugins/calendar/drivers/kolab/kolab_driver.php(1775): kolab_calend in /usr/share/php/kolabobject.php on line 171