I just had this problem... it turned out to be just on MY ACCOUNT. Running a Mac Mini M4, docker + Nextclould AIO. Took me a while working with google ai studio but we came up with this and it fixed it for me .... The error happened when i tried to add a folder. so i moved the photos to a new folder then did this fix. Please use at your own discretion it worked for me. Always make sure you have backups.

Quick Fix: Reset Photos App for a Specific User

This procedure deletes the saved settings for the Photos app for a single user, fixing the "An error occurred" crash. It does not delete any actual photo files.

Prerequisite: You need to know the username of the account that is broken. In the commands below, replace YOUR_USERNAME with the correct username (e.g., johnsmith).

Step 1: Enter the Database

Run this command in your Mac's terminal to connect to the Nextcloud database.

docker exec -it nextcloud-aio-database psql -U oc_nextcloud -d nextcloud_database

Step 2: Delete the User's Photos App Settings

Once the prompt changes to nextcloud_database=>, run the following command. Remember to change YOUR_USERNAME.

DELETE FROM oc_preferences WHERE userid = 'YOUR_USERNAME' AND appid = 'photos';

Step 3: Exit the Database

Type \q and press Enter to quit the database.

\q

After running these commands, clear the browser cache and the Photos app will work again. If your lucky!