Nextcloud PDF viewer highlighting layers by default

Nextcloud version : 22.2.0
Operating system and version : Ubuntu 20.04.3
Apache or nginx version : Nginx 1.21.3
PHP version : 8.0

The issue you are facing:
Shared PDFs are automatically rectangling layers when sharing files from autocad converted to PDF. Its really confusing to read PDF correctly.

Screen here:

Screenshot of the problem

InkedSnímek obrazovky 2021-10-06 194604_LI

Is this the first time you’ve seen this error?: Y

Steps to replicate it:

  1. Make file in Autocad and convert it to PDF
  2. Share the file
  3. Open the file via the shared link in nextcloud pdf viewer

The output of your Nextcloud log in Admin > Logging:

No event logs from the server
Everything works properly

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

<?php
$CONFIG = array (
  'instanceid' => '*',
  'passwordsalt' => '*',
  'secret' => '*',
  'trusted_domains' => 
  array (
    0 => 'cloud.*.cz',
  ),
  'trusted_proxies' => 
  array (
    0 => '192.*.*.98',
  ),
  'datadirectory' => '/var/www/nextcloud-data',
  'dbtype' => 'mysql',
  'version' => '22.2.0.2',
  'overwrite.cli.url' => 'https://cloud.*.cz',
  'overwritehost' => 'cloud.*.cz',
  'overwriteprotocol' => 'https',
  'dbname' => '*',
  'dbhost' => 'localhost:3306',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => '*',
  'dbpassword' => '*',
  'installed' => true,
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'redis' => 
  array (
    'host' => '/var/run/redis/redis-server.sock',
    'port' => 0,
    'timeout' => 0.0,
  ),
  'maintenance' => false,
  'default_language' => 'cs',
  'default_locale' => 'cs',
  'default_phone_region' => 'CZ',
  'theme' => '',
  'loglevel' => 2,
  'updater.release.channel' => 'stable',
  'mail_smtpmode' => 'smtp',
  'mail_sendmailmode' => 'smtp',
  'activity_expire_days' => 14,
  'auth.bruteforce.protection.enabled' => true,
  'blacklisted_files' => 
  array (
    0 => '.htaccess',
    1 => 'Thumbs.db',
    2 => 'thumbs.db',
  ),
  'cron_log' => true,
  'enable_previews' => true,
  'enabledPreviewProviders' => 
  array (
    0 => 'OC\\Preview\\PNG',
    1 => 'OC\\Preview\\JPEG',
    2 => 'OC\\Preview\\GIF',
    3 => 'OC\\Preview\\BMP',
    4 => 'OC\\Preview\\XBitmap',
    5 => 'OC\\Preview\\Movie',
    6 => 'OC\\Preview\\PDF',
    7 => 'OC\\Preview\\MP3',
    8 => 'OC\\Preview\\TXT',
    9 => 'OC\\Preview\\MarkDown',
  ),
  'filesystem_check_changes' => 0,
  'filelocking.enabled' => 'true',
  'htaccess.RewriteBase' => '/',
  'integrity.check.disabled' => false,
  'knowledgebaseenabled' => false,
  'logfile' => '/var/www/nextcloud.log',
  'logtimezone' => 'Europe/*',
  'log_rotate_size' => 104857600,
  'preview_max_x' => 1024,
  'preview_max_y' => 768,
  'preview_max_scale_factor' => 1,
  'quota_include_external_storage' => false,
  'skeletondirectory' => '',
  'trashbin_retention_obligation' => 'auto, 7',
);

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

No error log

So what to do with it? Is there a way to switch something in PDF viewer to not automatically rectangle layers ?

Reported on Github here > Nextcloud PDF viewer highlighting layers by default