imagesavealpha() expects parameter 1 to be resource, boolean given

[zsbolyoczki]

Steps to reproduce

Most probably relates to thumbnail generation:

sudo -u www-data php occ preview:generate-all

The exact message is:

imagesavealpha() expects parameter 1 to be resource, boolean given at ***/lib/private/legacy/image.php#571
imagesavealpha() expects parameter 1 to be resource, boolean given at ***/lib/private/legacy/image.php#572

Operating system:
Ubuntu 18.04.4 LTS

Web server:
apache2 - 2.4.29-1ubuntu4.13

Database:
mysql-5.7

PHP version:
php7.2-fpm

imagemagick 8:6.9.7.4+dfsg-16ubuntu6.8

Nextcloud version: (see Nextcloud admin page)
18.0.4 (currently the latest)

Updated from an older Nextcloud/ownCloud or fresh install:
started years ago and upgrading since then

Where did you install Nextcloud from:
official site

Signing status:

No errors have been found.

List of activated apps:

Enabled:
  - activity: 2.11.0
  - calendar: 2.0.3
  - cloud_federation_api: 1.1.0
  - contacts: 3.3.0
  - dav: 1.14.0
  - federatedfilesharing: 1.8.0
  - files: 1.13.1
  - files_fulltextsearch: 1.4.2
  - files_fulltextsearch_tesseract: 1.4.1
  - files_markdown: 2.2.0
  - files_mindmap: 0.0.21
  - files_rightclick: 0.15.2
  - files_sharing: 1.10.1
  - files_trashbin: 1.8.0
  - files_versions: 1.11.0
  - files_videoplayer: 1.7.0
  - firstrunwizard: 2.7.0
  - fulltextsearch: 1.4.1
  - fulltextsearch_elasticsearch: 1.5.1
  - logreader: 2.3.0
  - lookup_server_connector: 1.6.0
  - nextcloud_announcements: 1.7.0
  - notes: 3.3.0
  - notifications: 2.6.0
  - oauth2: 1.6.0
  - ocr: 6.0.37
  - password_policy: 1.8.0
  - passwords: 2020.5.0
  - photos: 1.0.0
  - previewgenerator: 2.3.0
  - privacy: 1.2.0
  - provisioning_api: 1.8.0
  - ransomware_protection: 1.6.1
  - settings: 1.0.0
  - sharebymail: 1.8.0
  - spreed: 8.0.8
  - tasks: 0.12.2
  - text: 2.0.0
  - theming: 1.9.0
  - twofactor_backupcodes: 1.7.0
  - updatenotification: 1.8.0
  - viewer: 1.2.0
  - workflowengine: 2.0.0

Nextcloud configuration:
What exact part is needed?

Are you using external storage, if yes which one: local/smb/sftp/...
No.

Are you using encryption: yes/no
No.

Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/...
No.

Client configuration

Browser:
N/A

Operating system:
N/A

Logs

Web server error log

Nothing related.

Browser log

N/A

[kesselb]

A image is broken. We can't create a preview. Yep we should check if a resource is given for imagesavealpha.

[szaimen]

Is this Issue still valid in NC21.0.2? If not, please close this issue. Thanks! :)

[ghost]

This issue has been automatically marked as stale because it has not had recent activity and seems to be missing some essential information. It will be closed if no further activity occurs. Thank you for your contributions.

[simonspa]

Yes, just appeared again yesterday on my instance with NC21.0.4:

[PHP] Error: Error: imagesavealpha() expects parameter 1 to be resource, bool given at /var/www/nextcloud/lib/private/legacy/OC_Image.php#589 at <<closure>>

 0. <<closure>>
    OC\Log\ErrorHandler::onError(2, "imagesavealpha( ... n", "/var/www/nextcl ... p", 589, {imagePath: "/ho ... 3})
 1. /var/www/nextcloud/lib/private/legacy/OC_Image.php line 589
    imagesavealpha(false, true)
 2. /var/www/nextcloud/lib/private/Preview/Image.php line 52
    OC_Image->loadFromFile("/home/data/next ... g")
 3. /var/www/nextcloud/lib/private/Preview/GeneratorHelper.php line 63
    OC\Preview\Image->getThumbnail(OC\Files\Node\File {}, 2048, 2048)
 4. /var/www/nextcloud/lib/private/Preview/Generator.php line 244
    OC\Preview\GeneratorHelper->getThumbnail(OC\Preview\PNG {}, OC\Files\Node\File {}, 2048, 2048)
 5. /var/www/nextcloud/lib/private/Preview/Generator.php line 140
    OC\Preview\Generator->getMaxPreview(OC\Files\SimpleFS\SimpleFolder {}, OC\Files\Node\File {}, "image/png", "")
 6. /var/www/nextcloud/lib/private/PreviewManager.php line 205
    OC\Preview\Generator->generatePreviews(OC\Files\Node\File {}, [{width: 32,heig ... "], "image/png")
 7. /var/www/nextcloud/apps/previewgenerator/lib/Command/PreGenerate.php line 217
    OC\PreviewManager->generatePreviews(OC\Files\Node\File {}, [{width: 32,heig ... "])
 8. /var/www/nextcloud/apps/previewgenerator/lib/Command/PreGenerate.php line 195
    OCA\PreviewGenerator\Command\PreGenerate->processFile(OC\Files\Node\File {})
 9. /var/www/nextcloud/apps/previewgenerator/lib/Command/PreGenerate.php line 163
    OCA\PreviewGenerator\Command\PreGenerate->processRow({id: "400781",ui ... "})
10. /var/www/nextcloud/apps/previewgenerator/lib/Command/PreGenerate.php line 131
    OCA\PreviewGenerator\Command\PreGenerate->startProcessing()
11. /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Command/Command.php line 255
    OCA\PreviewGenerator\Command\PreGenerate->execute(Symfony\Componen ... {}, Symfony\Componen ... {})
12. /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Application.php line 1009
    Symfony\Component\Console\Command\Command->run(Symfony\Componen ... {}, Symfony\Componen ... {})
13. /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Application.php line 273
    Symfony\Component\Console\Application->doRunCommand(OCA\PreviewGener ... {}, Symfony\Componen ... {}, Symfony\Componen ... {})
14. /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Application.php line 149
    Symfony\Component\Console\Application->doRun(Symfony\Componen ... {}, Symfony\Componen ... {})
15. /var/www/nextcloud/lib/private/Console/Application.php line 215
    Symfony\Component\Console\Application->run(Symfony\Componen ... {}, Symfony\Componen ... {})
16. /var/www/nextcloud/console.php line 100
    OC\Console\Application->run()
17. /var/www/nextcloud/occ line 11
    require_once("/var/www/nextcloud/console.php")

at 2021-08-17T22:00:03+02:00