Internal Server Error in admin panel / {"Exception":"Error","Message":"Class \"CnnFaceDetection\" not found"

[ghost]

Unable to load the admin page for Face Recognition. Any help would be greatly appreciated.

Ubuntu 22.04 installation with Nextcloud 27.1.2
pdlib and dlib are functioning correctly based on test script found here in github

Models 1-4 are installed, and all models have been chosen as default, but error message is the same.
Memory and other options have been made using 'occ' command line tool.

Personal option page for Face Recognition is working correctly, and "Analyze my images" option is selected.
Admin page for Face Recognition results in error message:

_Internal Server Error

The server was unable to complete your request.

If this happens again, please send the technical details below to the server administrator.

More details can be found in the server log.
Technical details

Remote Address: 102.129.152.203
Request ID: YzNb5zMdNODleUlu6pc2_

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Unable to configure the temporary area for image processing due to admin page not being accessible, resulting in this error:

_sudo -u www-data php /var/www/html/nextcloud/occ face:background_job

1/8 - Executing task CheckRequirementsTask (Check all requirements)
Seems that still don't configured the image area used for temporary files.
Please read the documentation about this: https://github.com/matiasdelellis/facerecognition/wiki/Settings#temporary-files
and then configure it in the admin panel to continue

Fill an issue here if that doesn't help: https://github.com/matiasdelellis/facerecognition/issues
Task CheckRequirementsTask signalled we should not continue, bailing out_

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set up face recognition settings

sudo -u www-data php /var/www/html/nextcloud/occ app:install facerecognition --force
sudo -u www-data php /var/www/html/nextcloud/occ app:enable facerecognition --force
sudo -u www-data php /var/www/html/nextcloud/occ face:setup -M 7.5G
sudo -u www-data php /var/www/html/nextcloud/occ face:setup --model 1
sudo -u www-data php /var/www/html/nextcloud/occ face:setup --model 2
sudo -u www-data php /var/www/html/nextcloud/occ face:setup --model 3
sudo -u www-data php /var/www/html/nextcloud/occ face:setup --model 4
sudo -u www-data php /var/www/html/nextcloud/occ config:app:set facerecognition sensitivity --value 0.4
sudo -u www-data php /var/www/html/nextcloud/occ config:app:set facerecognition max_image_area --value 786432
sudo -u www-data php /var/www/html/nextcloud/occ config:app:set facerecognition handle_external_files --value true
sudo -u www-data php /var/www/html/nextcloud/occ config:app:set facerecognition handle_shared_files --value false
sudo -u www-data php /var/www/html/nextcloud/occ config:app:set facerecognition min_image_size --value 128

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Logs show:

"File":"/var/www/html/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","Line":169,"Previous":{"Exception":"Error","Message":"Class "CnnFaceDetection" not found","Code":0,"Trace":[{"file":"/var/www/html/nextcloud/apps/facerecognition/lib/Settings/Admin.php","line":81,"function":"open","class":"OCA\FaceRecognition\Model\DlibCnnModel\DlibCnnModel","type":"->"},{"file":"/var/www/html/nextcloud/apps/settings/lib/Controller/CommonSettingsTrait.php","line":129,"function":"getForm","class":"OCA\FaceRecognition\Settings