After upgrading to Nextcloud 34.0.2 on TrueNAS SCALE, Photos no longer displays thumbnails.
Original photos are fully accessible:
- download works
- opening the original image works
- only previews/thumbnails fail
This affects all clients and multiple networks.
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## Environment
Nextcloud: 34.0.2
Installation:
TrueNAS SCALE official Nextcloud App
Database:
PostgreSQL 18
PHP:
(please insert output of php -v)
Storage:
Host path datasets
Application:
/mnt/Homestorage/Applications/Nextcloud/Appdata
Data:
/mnt/Homestorage/Applications/Nextcloud/Userdata
Preview location:
/var/www/html/data/appdata_oczmegtb93x8/preview
Apps enabled:
- Photos 7.0.0
- Recognize 12.0.0
- Maps 1.7.1
Preview Generator:
Disabled during troubleshooting
-–
## Problem
Photos only displays placeholder thumbnails.
Clicking the photo loads the original image correctly.
Downloads also work.
Every thumbnail request generates:
OCP\Files\NotFoundException:
Unable to open preview stream
Example:
Unable to open preview stream at
/var/www/html/data/appdata_oczmegtb93x8/preview/e/6/b/d/e/a/f/199658/3024-4032-max.jpg
-–
## Database observations
The original file exists:
SELECT *
FROM oc_filecache
WHERE fileid=199658;
returns the expected photo.
The preview table initially contained preview records.
After deleting them:
DELETE FROM oc_previews
WHERE file_id=199658;
Nextcloud recreates new rows automatically.
Example:
3024x4032 max
3024x3024 crop
1024x1024 crop
768x1024
etc.
However:
the corresponding preview files are never present on disk.
The preview directory for that file does not exist.
Therefore:
Database entries exist
Preview files do not exist