Preview is stopped working after upgrade from version 24 to 25.

[kevinkuan1969]

The Preview was working perfectly well before upgrade to version 25. After upgrade for 1 week, the Preview is not working entirely. Found all the answers and try it out but still cannot solve it.

We have tried the following methods:

• re-run the occ preview:generate-all -vvv
• re-run the occ files:scan-app-data
• Delete records from database mysql> delete from oc_filecache where path like "appdata_ocm2viqqd6xv/preview/%";
  • Delete the appdata folder root@cloud:/var/www/nextcloud/data/appdata_ocm2viqqd6xv# rm -rf preview
  • re-run preview generate command sudo -u www-data php occ preview:generate-all -vvv
  • ensure all the php is installed such as php-cli php-mysql php-gd php-xml php-mbsting php-zip and php-curl Still no clue and hope someone can help. Thanks

[kevinkuan1969]

Upgrade Nextcloud 24 to Nextcloud 25.0.2

[st3iny]

That is unfortunate but I can't reproduce it. I need more information to debug this.

• How about the list list enabled preview providers from config.php?
• Which OS are you using?
• Is this a dockerized setup?
• What do you mean by "Preview is not working entirely"? Are there errors when running occ preview:* commands or are no previews shown in the web ui?

[t-markmann]

I have a similar issue. NC 25.0.5.1 Current Apache with PHP 8.0

sudo -u www-data /var/www/nextcloud/occ preview:generate-all -vvv

In Application.php line 676:

  [Symfony\Component\Console\Exception\CommandNotFoundException]
  Command "preview:generate-all" is not defined.

  Did you mean one of these?
      notification:generate
      preview:repair
      preview:reset-rendered-texts

Exception trace:
  at /var/www/nextcloud/3rdparty/symfony/console/Application.php:676
 Symfony\Component\Console\Application->find() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:237
 Symfony\Component\Console\Application->doRun() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:149
 Symfony\Component\Console\Application->run() at /var/www/nextcloud/lib/private/Console/Application.php:214
 OC\Console\Application->run() at /var/www/nextcloud/console.php:100
 require_once() at /var/www/nextcloud/occ:11

Tried with and without pre-providers in config.php

  'enabledPreviewProviders' =>
  array (
    0 => 'OC\\Preview\\PNG',
    1 => 'OC\\Preview\\JPEG',
    2 => 'OC\\Preview\\GIF',
    3 => 'OC\\Preview\\HEIC',
    4 => 'OC\\Preview\\BMP',
    5 => 'OC\\Preview\\XBitmap',
    6 => 'OC\\Preview\\MP3',
    7 => 'OC\\Preview\\TXT',
    8 => 'OC\\Preview\\MarkDown',
    9 => 'OC\\Preview\\OpenDocument',
    10 => 'OC\\Preview\\Krita',
    11 => 'OC\\Preview\\TIFF',
  ),

Related to https://github.com/nextcloud/previewgenerator/issues/246 ?

Last time this worked was with NC 25.0.3. Yesterday I upgraded to 25.0.5.

Preview-generator App is installed and I even reinstalled. Still does not work.

[James-Oakley]

The issue is that you're using PHP 8.0. When I upgraded from NC24.x to NC25.x, the Apps settings screen in my installation shows that the Preview Generator app has been disabled.

This app cannot be installed because the following dependencies are not fulfilled:

• PHP with a version lower than 8.0 is required.

I'm not sure why this wasn't a problem before NC25.x - I have been using PHP 8.1 quite happily for a while with NextCloud ever since the main NextCloud system supported it. PHP 7.4 has been EOL since November 2022, so any web application today needs to support PHP 8.0 as a minimum.

So I'm unsure of the solution, but I think the upgrade script uninstalling the app is the cause of the problem

[James-Oakley]

So in my case, I checked the head of the code, saw it fully supported more recent PHP, and realised that I was several versions behind for this app. Checking out to the latest tag fixed the problems

[st3iny]

That is odd. I pushed a fixed release that adds the support for PHP 7.4 again as it's supported by Nextcloud 25. It should support PHP v7.4 up to v8.2.

Try to reinstall/update the app and make sure that it tries to install previewgenerator v5.3.0 which is the most recent release.

[James-Oakley]

That is odd. I pushed a fixed release that adds the support for PHP 7.4 again as it's supported by Nextcloud 25. It should support PHP v7.4 up to v8.2.

Try to reinstall/update the app and make sure that it tries to install previewgenerator v5.3.0 which is the most recent release.

I'm now all happy. My problem, I think, was that I installed it into /apps originally using git clone instead of the app manager within the installation. As a result, it hadn't updated for ages, because I was being left to do that manually. Running git checkout on the latest release tag fixed it all

[st3iny]

Closing as this seems to be resolved now.