Issue on chunk * has no owner

Hello,

I currently have some problems to pack my backups.
I always get this error after the RestoringChunk it currently works on, after I start it again it continues with the next but fails again at the end:

I configured to save the app_data on an external local storage. And upload them to an external ftps server.

I mounted the local Nextcloudbackup over the /etc/fstab like that:

#/NextCloudData
/dev/disk/by-uuid/08d82353-ca4b-4616-ba04-df6793fba63b /NextCloudData ext4 defaults 0 1
#/NextCloudBackup
/dev/disk/by-uuid/608df94a-c236-42cd-8704-a252ad4d57f0 /NextCloudBackup ext4 defaults 0 1

I assigned all the permissions to the folder with

chmod -R www-data:www-data /NextCloudBackup

I can normally use and access the files inside the /NextCloudBackup external storage showing in Nextcloud Files. So it can't be a permission problem somehow? Im confused....

Anyone got an idea what it could be?

Start by reviewing the RestoringChunk failure shown in the issue and reproduce the backup with app_data on the mounted /NextCloudBackup path and upload configured to the external FTPS server. Compare the configured paths and permissions with the failure, then confirm the cause by completing a backup without the chunk error.