Nextcloud version (eg, 12.0.2): 18.0.1
Operating system and version (eg, Ubuntu 17.04): Centos 7.7.1908
Apache or nginx version (eg, Apache 2.4.25): Apache 2.4.6
PHP version (eg, 7.1): 7.2.27
The issue you are facing:
After upgrading from 17 to 18 manually and amazingly 
rather smoothly everything seems to be working fine. But I now get tons of debug information the significance of which I am not quite certain of. Debug information # 2 (see below) is related to our group calendar. It pops up every time a client synchronizes. The client software is Thunderbird 68.5.0 with Lightning and add-ons “TbSync 2.11” and “Provider for CalDAV & CardDAV 1.9”.
Is this the first time you’ve seen this error? (Y/N): Y
Steps to replicate it:
The output of your Nextcloud log in Admin > Logging:
#1
Deprecated event type for \OCP\Files::postWrite: Symfony\Component\EventDispatcher\GenericEvent
#2
Sabre\DAV\Exception\NotAuthenticated: No public access to this resource., No ‘Authorization: Basic’ header found. Either the client didn’t send one, or the server is misconfigured, No ‘Authorization: Bearer’ header found. Either the client didn’t send one, or the server is mis-configured, No ‘Authorization: Basic’ header found. Either the client didn’t send one, or the server is misconfigured
0. <>
Sabre\DAV\Auth\Plugin->beforeMethod(Sabre\HTTP\R … "}, Sabre\HTTP\Response {})
- /home/nextcloud/3rdparty/sabre/event/lib/EventEmitterTrait.php - line 105:
call_user_func_array([ Sabre\DAV\ … "], [ Sabre\HTTP … }]) - /home/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php - line 466:
Sabre\Event\EventEmitter->emit(“beforeMethod”, [ Sabre\HTTP … }]) - /home/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php - line 254:
Sabre\DAV\Server->invokeMethod(Sabre\HTTP\R … "}, Sabre\HTTP\Response {}) - /home/nextcloud/apps/dav/lib/Server.php - line 319:
Sabre\DAV\Server->exec() - /home/nextcloud/apps/dav/appinfo/v2/remote.php - line 35:
OCA\DAV\Server->exec() - /home/nextcloud/remote.php - line 165:
require_once("/home/nextcl … p")
The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
<?php
$CONFIG = array (
'appcodechecker' => true,
'appstoreenabled' => true,
'appstore.experimental.enabled' => true,
'updatechecker' => false,
'instanceid' => '[secret]',
'passwordsalt' => '[secret]',
'secret' => '[secret]',
'trusted_domains' =>
array (
0 => '[myserver]',
),
'datadirectory' => '/home/nextcloud/data',
'overwrite.cli.url' => 'https://[myserver]',
'dbtype' => 'mysql',
'version' => '18.0.1.3',
'dbname' => 'oc',
'dbhost' => 'localhost',
'dbtableprefix' => 'oc_',
'dbuser' => 'oc',
'dbpassword' => '[secret]',
'logfile' => '/var/log/nextcloud.log',
'logtimezone' => 'Europe/Berlin',
'loglevel' => 0,
'installed' => true,
'auth.bruteforce.protection.enabled' => false,
'memcache.local' => '\\OC\\Memcache\\APCu',
'mail_smtpmode' => 'sendmail',
'mail_domain' => '[my_maildomain]',
'default_language' => 'en',
'defaultapp' => 'files',
'knowledgebaseenabled' => true,
'enable_avatars' => true,
'session_keepalive' => true,
'skeletondirectory' => '',
'theme' => '',
'maintenance' => false,
'mail_from_address' => 'oc',
'mail_sendmailmode' => 'smtp',
'app_install_overwrite' =>
array (
0 => 'calendar',
),
);
The output of your Apache/nginx/system log in /var/log/____:
[my_ip] - - [04/Mar/2020:11:48:26 +0100] "PROPFIND /remote.php/dav/principals/users/[my_account]/ HTTP/1.1" 401 557 "-" "Thunderbird CalDAV/CardDAV Lightning/68.5.0"
[my_ip] - [my_account] [04/Mar/2020:11:48:26 +0100] "PROPFIND /remote.php/dav/principals/users/[my_account]/ HTTP/1.1" 207 776 "-" "Thunderbird CalDAV/CardDAV Lightning/68.5.0"
[my_ip] - - [04/Mar/2020:11:48:27 +0100] "PROPFIND /remote.php/dav/principals/groups/admin/ HTTP/1.1" 401 557 "-" "Thunderbird CalDAV/CardDAV Lightning/68.5.0"
[my_ip] - [my_account] [04/Mar/2020:11:48:27 +0100] "PROPFIND /remote.php/dav/principals/groups/admin/ HTTP/1.1" 207 459 "-" "Thunderbird CalDAV/CardDAV Lightning/68.5.0"
[my_ip] - [my_account] [04/Mar/2020:11:48:28 +0100] "PROPFIND /remote.php/dav/principals/groups/gf/ HTTP/1.1" 207 456 "-" "Thunderbird CalDAV/CardDAV Lightning/68.5.0"
[my_ip] - - [04/Mar/2020:11:48:28 +0100] "PROPFIND /remote.php/dav/principals/groups/[my_company]/ HTTP/1.1" 401 557 "-" "Thunderbird CalDAV/CardDAV Lightning/68.5.0"
[my_ip] - [my_account] [04/Mar/2020:11:48:28 +0100] "PROPFIND /remote.php/dav/principals/groups/[my_company]/ HTTP/1.1" 207 464 "-" "Thunderbird CalDAV/CardDAV Lightning/68.5.0"
[my_ip] - - [04/Mar/2020:11:48:29 +0100] "PROPFIND /remote.php/dav/calendars/[my_account]/ HTTP/1.1" 401 557 "-" "Thunderbird CalDAV/CardDAV Lightning/68.5.0"
[my_ip] - [my_account] [04/Mar/2020:11:48:29 +0100] "PROPFIND /remote.php/dav/calendars/[my_account]/ HTTP/1.1" 207 11083 "-" "Thunderbird CalDAV/CardDAV Lightning/68.5.0"
[my_ip] - [my_account] [04/Mar/2020:11:48:29 +0100] "REPORT /remote.php/dav/calendars/[my_account]/an-abwesenheiten_shared_by_[someoneelse]/ HTTP/1.1" 207 314 "-" "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 Lightning/68.5.0"