Icons not showing in alarm mails (the logo does)

Nextcloud version (eg, 20.0.5): 23.0.4
Operating system and version (eg, Ubuntu 20.04): Debian 11
Apache or nginx version (eg, Apache 2.4.25): 2.4.53
PHP version (eg, 7.4): 7.4

The issue you are facing:

Is this the first time you’ve seen this error? (Y/N): Y

Steps to replicate it:

  1. Receive an EMail with notifcations
  2. the logo is showing but the icons aren’t
  3. By calling the path of the icon directly it shows up

The output of your config.php file in /var/www/nextcloud (nextcloud root is /):

<?php
$CONFIG = array (
  'instanceid' => 'xx',
  'passwordsalt' => 'xx',
  'secret' => 'xx',
  'trusted_domains' =>
  array (
    0 => '192.168.10.10',
    1 => 'xx',
  ),
  'default_phone_region' => 'ISO 3166-2:CH',
  'datadirectory' => '/nc-data',
  'dbtype' => 'mysql',
  'version' => '23.0.4.1',
  'overwrite.cli.url' => 'https://xx.xx.xx/',
  'forcessl' => true,
  'overwriteprotocol' => 'https',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'memcache.local' => '\\OC\\Memcache\\Redis',
  'mysql.utf8mb4' => true,
  'dbuser' => 'nextcloud',
  'dbpassword' => 'xx',
  'skeletondirectory' => '',
  'installed' => true,
  'maintenance' => false,
  'theme' => '',
  'loglevel' => 2,
  'mail_smtpmode' => 'smtp',
  'mail_smtpsecure' => 'tls',
  'mail_sendmailmode' => 'smtp',
  'mail_from_address' => 'xx@xx.xx',
  'mail_domain' => 'xx',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_smtpauth' => 1,
  'mail_smtpport' => '587',
  'mail_smtphost' => 'xx.xx.xx.xx',
  'mail_smtpname' => 'xx@xx.x',
  'mail_smtppassword' => 'xx',
  'trusted_proxies' =>
  array (
    0 => '192.168.10.9',
  ),
  'updater.release.channel' => 'stable',
);

The output of your Apache/nginx/system log in /var/log/____:

30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/logo/logo.png?v=32 HTTP/1.1" 304 2001 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/download.svg HTTP/1.1" 304 2000 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /core/img/actions/downloadsvg HTTP/1.1" 302 2430 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"
192.168.10.9 - - [18/May/2022:17:31:25 +0200] "GET /index.php/login HTTP/1.1" 200 8954 "-" "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; Microsoft Outlook 14.0.7268; ms-office; MSOffice 14)"