[Solved] Image Previews only working for HEIC photos

[Lucas_E]

Nextcloud version (eg, 20.0.5): 27.0.0
Operating system and version (eg, Ubuntu 20.04): Ubuntu 22.04.2 LTS x86_64
Apache or nginx version (eg, Apache 2.4.25): Apache/2.4.52
PHP version (eg, 7.4): 8.2

The issue you are facing:

Hello to the Nextcloud community

I currently cannot get image previews going except for HEIC images. HEIC images show previews, but everything else, including all other image types, documents, etcetera do not show any image previews.

I don’t honestly remember if those image previews were working before I enabled HEIC images. I tried disabling HEIC image support by removing the HEIC line from the config.php, but that makes my server crash.

The output of your Nextcloud log in Admin > Logging:

Error	PHP	Using ${var} in strings is deprecated, use {$var} instead at /var/www/nextcloud/apps/mail/vendor/voku/portable-utf8/src/voku/helper/UTF8.php#13409		2023-06-16T14:46:11-0400
Error	PHP	Using ${var} in strings is deprecated, use {$var} instead at /var/www/nextcloud/apps/mail/vendor/voku/portable-utf8/src/voku/helper/UTF8.php#13409		2023-06-16T14:23:58-0400
Error	PHP	Using ${var} in strings is deprecated, use {$var} instead at /var/www/nextcloud/apps/mail/vendor/voku/portable-utf8/src/voku/helper/UTF8.php#13409		2023-06-16T14:17:57-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T14:14:12-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T14:12:20-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T14:11:22-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T14:10:01-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T14:09:14-0400
Error	webdav	InvalidArgumentException: X-OC-MTime header must be a valid positive integer		2023-06-16T14:00:16-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:57:31-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:57:30-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:57:22-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:57:01-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:56:31-0400
Error	PHP	Using ${var} in strings is deprecated, use {$var} instead at /var/www/nextcloud/apps/mail/vendor/voku/portable-utf8/src/voku/helper/UTF8.php#13409		2023-06-16T13:48:19-0400
Error	PHP	Using ${var} in strings is deprecated, use {$var} instead at /var/www/nextcloud/apps/mail/vendor/voku/portable-utf8/src/voku/helper/UTF8.php#13409		2023-06-16T13:47:09-0400
Error	PHP	Using ${var} in strings is deprecated, use {$var} instead at /var/www/nextcloud/apps/mail/vendor/voku/portable-utf8/src/voku/helper/UTF8.php#13409		2023-06-16T13:45:37-0400
Error	PHP	Using ${var} in strings is deprecated, use {$var} instead at /var/www/nextcloud/apps/mail/vendor/voku/portable-utf8/src/voku/helper/UTF8.php#13409		2023-06-16T13:43:15-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:39:54-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:29:06-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:28:32-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:28:02-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:27:32-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:27:02-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:26:32-0400
Error	no app in context	Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45		2023-06-16T13:26:02-0400
Error	PHP	Using ${var} in strings is deprecated, use {$var} instead at /var/www/nextcloud/apps/mail/vendor/voku/portable-utf8/src/voku/helper/UTF8.php#13409		2023-06-16T13:25:50-0400
Error	PHP	Allowed memory size of 134217728 bytes exhausted (tried to allocate 263103560 bytes) at /var/www/nextcloud/lib/private/Installer.php#299		2023-06-16T13:25:40-0400

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

<?php
$CONFIG = array (
  'instanceid' => 'ocdytz39duu6',
  'passwordsalt' => 'hidden',
  'secret' => 'hiden',
  'trusted_domains' =>
  array (
    0 => 'hidden.domain.com',
  ),
  'datadirectory' => '/10tb/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '27.0.0.8',
  'overwrite.cli.url' => 'https://mydomain.hidden',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'hidden',
  'dbpassword' => 'hidden',
  'installed' => true,
  'maintenance' => false,
  'enable_previews' => true,
  'enabledPreviewProviders' => [
  'OC\\Preview\\HEIC',
],
);

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

[Fri Jun 16 17:24:23.469501 2023] [mpm_prefork:notice] [pid 31459] AH00170: caught SIGWINCH, shutting down gracefully
Created directory: /var/lib/snmp/cert_indexes
[Fri Jun 16 17:24:23.573659 2023] [mpm_prefork:notice] [pid 35683] AH00163: Apache/2.4.52 (Ubuntu) OpenSSL/3.0.2 configured -- resuming normal operations
[Fri Jun 16 17:24:23.573703 2023] [core:notice] [pid 35683] AH00094: Command line: '/usr/sbin/apache2'
[Fri Jun 16 17:25:40.990277 2023] [php:error] [pid 35684] [client 73.123.37.53:61925] PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted (tried to allocate 263103560 bytes) in /var/www/nextclo>[Fri Jun 16 17:29:13.376917 2023] [access_compat:error] [pid 35690] [client 73.123.37.53:62192] AH01797: client denied by server configuration: /var/www/nextcloud/data/.ocdata
[Fri Jun 16 17:43:10.400279 2023] [mpm_prefork:notice] [pid 35683] AH00170: caught SIGWINCH, shutting down gracefully
[Fri Jun 16 17:43:10.544235 2023] [mpm_prefork:notice] [pid 36346] AH00163: Apache/2.4.52 (Ubuntu) OpenSSL/3.0.2 configured -- resuming normal operations
[Fri Jun 16 17:43:10.544289 2023] [core:notice] [pid 36346] AH00094: Command line: '/usr/sbin/apache2'
[Fri Jun 16 17:45:33.547472 2023] [mpm_prefork:notice] [pid 36346] AH00170: caught SIGWINCH, shutting down gracefully
[Fri Jun 16 17:45:33.676455 2023] [mpm_prefork:notice] [pid 36408] AH00163: Apache/2.4.52 (Ubuntu) OpenSSL/3.0.2 configured -- resuming normal operations
[Fri Jun 16 17:45:33.676502 2023] [core:notice] [pid 36408] AH00094: Command line: '/usr/sbin/apache2'
[Fri Jun 16 17:46:50.505953 2023] [mpm_prefork:notice] [pid 36408] AH00170: caught SIGWINCH, shutting down gracefully
[Fri Jun 16 17:46:50.642991 2023] [mpm_prefork:notice] [pid 36443] AH00163: Apache/2.4.52 (Ubuntu) OpenSSL/3.0.2 configured -- resuming normal operations
[Fri Jun 16 17:46:50.643039 2023] [core:notice] [pid 36443] AH00094: Command line: '/usr/sbin/apache2'
[Fri Jun 16 17:48:13.970201 2023] [mpm_prefork:notice] [pid 36443] AH00170: caught SIGWINCH, shutting down gracefully
[Fri Jun 16 17:48:14.109958 2023] [mpm_prefork:notice] [pid 36494] AH00163: Apache/2.4.52 (Ubuntu) OpenSSL/3.0.2 configured -- resuming normal operations
[Fri Jun 16 17:48:14.110003 2023] [core:notice] [pid 36494] AH00094: Command line: '/usr/sbin/apache2'
[Fri Jun 16 18:17:55.931521 2023] [mpm_prefork:notice] [pid 36494] AH00170: caught SIGWINCH, shutting down gracefully
[Fri Jun 16 18:17:56.048432 2023] [mpm_prefork:notice] [pid 39584] AH00163: Apache/2.4.52 (Ubuntu) OpenSSL/3.0.2 configured -- resuming normal operations
[Fri Jun 16 18:17:56.048586 2023] [core:notice] [pid 39584] AH00094: Command line: '/usr/sbin/apache2'
[Fri Jun 16 18:23:55.385028 2023] [mpm_prefork:notice] [pid 39584] AH00170: caught SIGWINCH, shutting down gracefully
[Fri Jun 16 18:23:55.532970 2023] [mpm_prefork:notice] [pid 39745] AH00163: Apache/2.4.52 (Ubuntu) OpenSSL/3.0.2 configured -- resuming normal operations
[Fri Jun 16 18:23:55.533018 2023] [core:notice] [pid 39745] AH00094: Command line: '/usr/sbin/apache2'
[Fri Jun 16 18:42:09.095094 2023] [php:error] [pid 53965] [client 51.12.216.100:57571] script '/var/www/nextcloud/xmlrpc.php' not found or unable to stat
[Fri Jun 16 18:45:50.992823 2023] [php:error] [pid 52489] [client 73.123.37.53:50480] PHP Parse error:  Unclosed '(' on line 2 does not match ']' in /var/www/nextcloud/config/config.php on line 23
[Fri Jun 16 18:45:54.222975 2023] [mpm_prefork:notice] [pid 39745] AH00170: caught SIGWINCH, shutting down gracefully
[Fri Jun 16 18:45:54.360739 2023] [mpm_prefork:notice] [pid 54117] AH00163: Apache/2.4.52 (Ubuntu) OpenSSL/3.0.2 configured -- resuming normal operations
[Fri Jun 16 18:45:54.360884 2023] [core:notice] [pid 54117] AH00094: Command line: '/usr/sbin/apache2'
[Fri Jun 16 18:45:56.568776 2023] [php:error] [pid 54119] [client 73.123.37.53:50487] PHP Parse error:  Unclosed '(' on line 2 does not match ']' in /var/www/nextcloud/config/config.php on line 23
[Fri Jun 16 18:45:57.474431 2023] [php:error] [pid 54120] [client 73.123.37.53:50488] PHP Parse error:  Unclosed '(' on line 2 does not match ']' in /var/www/nextcloud/config/config.php on line 23
[Fri Jun 16 18:45:59.050397 2023] [php:error] [pid 54121] [client 73.123.37.53:50490] PHP Parse error:  Unclosed '(' on line 2 does not match ']' in /var/www/nextcloud/config/config.php on line 23, referer: h>[Fri Jun 16 18:46:03.280710 2023] [php:error] [pid 54123] [client 73.123.37.53:50492] PHP Parse error:  Unclosed '(' on line 2 does not match ']' in /var/www/nextcloud/config/config.php on line 23
[Fri Jun 16 18:46:03.280709 2023] [php:error] [pid 54122] [client 73.123.37.53:50493] PHP Parse error:  Unclosed '(' on line 2 does not match ']' in /var/www/nextcloud/config/config.php on line 23
[Fri Jun 16 18:46:09.365755 2023] [mpm_prefork:notice] [pid 54117] AH00170: caught SIGWINCH, shutting down gracefully
[Fri Jun 16 18:46:09.466959 2023] [mpm_prefork:notice] [pid 54142] AH00163: Apache/2.4.52 (Ubuntu) OpenSSL/3.0.2 configured -- resuming normal operations
[Fri Jun 16 18:46:09.467004 2023] [core:notice] [pid 54142] AH00094: Command line: '/usr/sbin/apache2'

I also installed the image preview generator app. I can run it and it completes without errors. Example output:

2023-06-16T19:10:07+00:00 Generating previews for /jakem/files/USB Drive Recovery/week 7 discussion WCC.docx
2023-06-16T19:10:07+00:00 Generating previews for /jakem/files/USB Drive Recovery/week7 paper WWC - opinion.docx
2023-06-16T19:10:07+00:00 Generating previews for /jakem/files/USB Drive Recovery/white collar crime and gender- opinion.docx
2023-06-16T19:10:07+00:00 Generating previews for /jakem/files/USB Drive Recovery/white collar crime week 1.docx
2023-06-16T19:10:07+00:00 Generating previews for /jakem/files/USB Drive Recovery/youth probabtion.docx
2023-06-16T19:10:07+00:00 Generating previews for /jakem/files/USB Drive Recovery/youth probation.docx
srvr01@server:~$

This is a new install, with some files brought over from an owncloud setup (downloaded via owncloud then uploaded via nextcloud, it was not updated or moved over internally)

[wwe]

hi Lucas_E maybe this thread will help you further

HEIC Previews and mov playback non IOS

Hi hoping to get some advice. Is this link/instructions a safe and privacy free way to get heic previews working and would it work the same on 22.04? Or does it share the same privacy/performance concerns that are listed here regarding HEIC: https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/config_sample_php_parameters.html And what are the concerns for HEIC here ^ Also, my iphone is set to take heic format photos yet my uploads in camera upload folder are all JPG.…

[Lucas_E]

Hi @wwe thank you for the reply. That’s actually the opposite of my issue. HEIC images are working fine, all other formats do not show previews.

[jtr]

I see three things:

• Your difficulty disabling the previews was likely due to a stray bracket left when you tried to remove it from your config.php (see below)
• Error logs indicate your PHP environment is running with memory_limit set below the minimum which may cause some things to fail
• The errors about IntlBreakIterator will need a full stack trace to isolate - please post the Copy raw contents (far right of the entry in Logging will show a clipboard icon where this option will be available) from your logs for one of those entries
• Check your browser console to see which request is generating that broken image and match it to a transaction entry in your Nextcloud logs

 'enabledPreviewProviders' => [
 'OC\\Preview\\HEIC',
],

Note: Leave the ); after these three lines

[Lucas_E]

Ill take a look at those.

The memory limit is an old error, It’s at 800mb now I believe.

[Lucas_E]

Here’s one of the intlHBreakIterator errors:

{"reqId":"N0NpyJccZUM21VVJvpCk","level":3,"time":"2023-06-16T17:26:32+00:00","remoteAddr":"hiddenip","user":"myusername","app":"no app in context","method":"GET","url":"/ocs/v2.php/apps/spreed/api/v4/room","message":"Class \"IntlBreakIterator\" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45","userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36","version":"27.0.0.8","exception":{"Exception":"Exception","Message":"Class \"IntlBreakIterator\" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45","Code":0,"Trace":[{"file":"/var/www/nextcloud/lib/private/AppFramework/App.php","line":183,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/var/www/nextcloud/lib/private/Route/Router.php","line":315,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/var/www/nextcloud/ocs/v1.php","line":64,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/var/www/nextcloud/ocs/v2.php","line":23,"args":["/var/www/nextcloud/ocs/v1.php"],"function":"require_once"}],"File":"/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","Line":169,"Previous":{"Exception":"Error","Message":"Class \"IntlBreakIterator\" not found","Code":0,"Trace":[{"file":"/var/www/nextcloud/apps/spreed/lib/Service/AvatarService.php","line":344,"function":"isValidSingleEmoji","class":"OC\\EmojiHelper","type":"->"},{"file":"/var/www/nextcloud/apps/spreed/lib/Service/RoomFormatter.php","line":138,"function":"getAvatarVersion","class":"OCA\\Talk\\Service\\AvatarService","type":"->"},{"file":"/var/www/nextcloud/apps/spreed/lib/Service/RoomFormatter.php","line":72,"function":"formatRoomV4","class":"OCA\\Talk\\Service\\RoomFormatter","type":"->"},{"file":"/var/www/nextcloud/apps/spreed/lib/Controller/RoomController.php","line":392,"function":"formatRoom","class":"OCA\\Talk\\Service\\RoomFormatter","type":"->"},{"file":"/var/www/nextcloud/apps/spreed/lib/Controller/RoomController.php","line":259,"function":"formatRoom","class":"OCA\\Talk\\Controller\\RoomController","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":230,"function":"getRooms","class":"OCA\\Talk\\Controller\\RoomController","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":137,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/App.php","line":183,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/var/www/nextcloud/lib/private/Route/Router.php","line":315,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/var/www/nextcloud/ocs/v1.php","line":64,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/var/www/nextcloud/ocs/v2.php","line":23,"args":["/var/www/nextcloud/ocs/v1.php"],"function":"require_once"}],"File":"/var/www/nextcloud/lib/private/EmojiHelper.php","Line":45},"CustomMessage":"--"},"id":"648fda1c81f5d"}

Here it is formatted:

[no app in context] Error: Exception: Class "IntlBreakIterator" not found in file '/var/www/nextcloud/lib/private/EmojiHelper.php' line 45 at <<closure>>

0. /var/www/nextcloud/lib/private/AppFramework/App.php line 183
   OC\AppFramework\Http\Dispatcher->dispatch()
1. /var/www/nextcloud/lib/private/Route/Router.php line 315
   OC\AppFramework\App::main()
2. /var/www/nextcloud/ocs/v1.php line 64
   OC\Route\Router->match()
3. /var/www/nextcloud/ocs/v2.php line 23
   require_once("/var/www/nextcloud/ocs/v1.php")

Caused by:

Error: Class "IntlBreakIterator" not found at <<closure>>

 0. /var/www/nextcloud/apps/spreed/lib/Service/AvatarService.php line 344
    OC\EmojiHelper->isValidSingleEmoji()
 1. /var/www/nextcloud/apps/spreed/lib/Service/RoomFormatter.php line 138
    OCA\Talk\Service\AvatarService->getAvatarVersion()
 2. /var/www/nextcloud/apps/spreed/lib/Service/RoomFormatter.php line 72
    OCA\Talk\Service\RoomFormatter->formatRoomV4()
 3. /var/www/nextcloud/apps/spreed/lib/Controller/RoomController.php line 392
    OCA\Talk\Service\RoomFormatter->formatRoom()
 4. /var/www/nextcloud/apps/spreed/lib/Controller/RoomController.php line 259
    OCA\Talk\Controller\RoomController->formatRoom()
 5. /var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php line 230
    OCA\Talk\Controller\RoomController->getRooms()
 6. /var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php line 137
    OC\AppFramework\Http\Dispatcher->executeController()
 7. /var/www/nextcloud/lib/private/AppFramework/App.php line 183
    OC\AppFramework\Http\Dispatcher->dispatch()
 8. /var/www/nextcloud/lib/private/Route/Router.php line 315
    OC\AppFramework\App::main()
 9. /var/www/nextcloud/ocs/v1.php line 64
    OC\Route\Router->match()
10. /var/www/nextcloud/ocs/v2.php line 23
    require_once("/var/www/nextcloud/ocs/v1.php")

GET /ocs/v2.php/apps/spreed/api/v4/room
from hiddenup by username at 2023-06-16T17:26:32+00:00

As far as the console, I get a lot of “jQuery is depcreceted” errors, no image related errors anywhere. Still no icons.

Those errors were right after install. I’ve recreated previews a couple of times, and there are no errors in the logs other than a couple of failed logins from the last 2 days (an old owncloud client trying to sign in)

[Lucas_E]

The issue is resolved by removing the line that enables HEIC support:

  'enabledPreviewProviders' => [
  'OC\\Preview\\HEIC',
],

So this config file works for most file types but not HEIC images:

<?php
$CONFIG = array (
  'instanceid' => 'ocdytz39duu6',
  'passwordsalt' => 'no',
  'secret' => 'no',
  'trusted_domains' =>
  array (
    0 => 'domain.domain',
  ),
  'datadirectory' => '/10tb/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '27.0.0.8',
  'overwrite.cli.url' => 'https://domain.domain',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'bulkupload.enabled' => false,
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'not',
  'dbpassword' => 'no',
  'installed' => true,
  'maintenance' => false,
  'enable_previews' => true,
);

This one works for HEIC images, but nothing else:

<?php
$CONFIG = array (
  'instanceid' => 'ocdytz39duu6',
  'passwordsalt' => 'no',
  'secret' => 'no',
  'trusted_domains' =>
  array (
    0 => 'domain.domain',
  ),
  'datadirectory' => '/10tb/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '27.0.0.8',
  'overwrite.cli.url' => 'https://domain.domain',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'bulkupload.enabled' => false,
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'not',
  'dbpassword' => 'no',
  'installed' => true,
  'maintenance' => false,
  'enable_previews' => true,
  'enabledPreviewProviders' => [
  'OC\\Preview\\HEIC',
],
);

How can I have both?

[Lucas_E]

Looks like I do actually have to list all types.

https://www.reddit.com/r/NextCloud/comments/rwu0sh/heic_preview_support/

Solved.

Fixed config ends with:

  'maintenance' => false,
  'enable_previews' => true,
  'enabledPreviewProviders' =>
  array (
    'OC\Preview\PNG',
    'OC\Preview\JPEG',
    'OC\Preview\GIF',
    'OC\Preview\BMP',
    'OC\Preview\XBitmap',
    'OC\Preview\MP3',
    'OC\Preview\TXT',
    'OC\Preview\MarkDown',
    'OC\Preview\OpenDocument',
    'OC\Preview\Krita',
    'OC\Preview\HEIC',
  ),
);