Unable to backup sftperror

I am suddenly (The past several weeks) unable to backup on two seperate machines, and I am not sure how to interpret the errors. I do not see any errors on the host server logs (unraid) or in the sftp logs. The duplicati logs are attached.

        {

“DeletedFiles”: 969973,
“DeletedFolders”: 138028,
“ModifiedFiles”: 695,
“ExaminedFiles”: 44353,
“OpenedFiles”: 3354,
“AddedFiles”: 2659,
“SizeOfModifiedFiles”: 491554090,
“SizeOfAddedFiles”: 640686196,
“SizeOfExaminedFiles”: 32476151073,
“SizeOfOpenedFiles”: 1144078159,
“NotProcessedFiles”: 0,
“AddedFolders”: 255,
“TooLargeFiles”: 0,
“FilesWithError”: 0,
“ModifiedFolders”: 0,
“ModifiedSymlinks”: 0,
“AddedSymlinks”: 0,
“DeletedSymlinks”: 29,
“PartialBackup”: false,
“Dryrun”: false,
“MainOperation”: “Backup”,
“CompactResults”: null,
“VacuumResults”: null,
“DeleteResults”: null,
“RepairResults”: null,
“TestResults”: null,
“ParsedResult”: “Fatal”,
“Interrupted”: false,
“Version”: “2.1.0.5 (2.1.0.5_stable_2025-03-04)”,
“EndTime”: “2025-06-16T04:25:41.7470723Z”,
“BeginTime”: “2025-06-16T04:22:24.6583514Z”,
“Duration”: “00:03:17.0887209”,
“MessagesActualLength”: 129,
“WarningsActualLength”: 136,
“ErrorsActualLength”: 2,
“Messages”: [
“2025-06-15 23:22:24 -05 - [Information-Duplicati.Library.Main.Controller-StartingOperation]: The operation Backup has started”,
“2025-06-15 23:23:44 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: List - Started: ()”,
“2025-06-15 23:23:45 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: List - Completed: (107.14 KB)”,
“2025-06-15 23:23:46 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-RemoteUnwantedMissingFile]: removing file listed as Temporary: duplicati-20250615T225713Z.dlist.zip.aes”,
“2025-06-15 23:23:46 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-20250615T225714Z.dlist.zip.aes”,
“2025-06-15 23:23:47 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-KeepIncompleteFile]: keeping protected incomplete remote file listed as Uploading: duplicati-20250616T041535Z.dlist.zip.aes”,
“2025-06-15 23:23:47 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-bb2b26f918632450ca6d940624091773d.dblock.zip.aes”,
“2025-06-15 23:23:48 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-b5e5070e3c16f42a8a4c62aecca6e88ce.dblock.zip.aes”,
“2025-06-15 23:23:48 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-b570c4fe9219c43f892affc2fa9e862e3.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-b21820326b01944af89f67d90f409eb37.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-b9a840bd0dea447f987d5ffaee815ed62.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-b6219d3557a4a4d00ab986790c57f65c5.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-bfa12d35037bd411fb9d85a65a6fb863c.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-bf4c74a68dc254224b2de04d7155a7ad1.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-b26cb4e456fd447948388d2e728697e3d.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-b52114ed0026644cb9cf152130e8f922c.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-ba1a64310256e420b8efabb7ac65789de.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-SchedulingMissingFileForDelete]: scheduling missing file for deletion, currently listed as Uploading: duplicati-bebf705099bc0434aa45a3d509efbd439.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-RemoteUnwantedMissingFile]: removing file listed as Deleting: duplicati-b4511b40dd94f47e9a97fd7f03c6b1206.dblock.zip.aes”,
“2025-06-15 23:23:49 -05 - [Information-Duplicati.Library.Main.Operation.FilelistProcessor-RemoteUnwantedMissingFile]: removing file listed as Deleting: duplicati-ba7fb31f06add42b8aa7f6e27438456fd.dblock.zip.aes”
],
“Warnings”: [
“2025-06-15 23:24:24 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\NTUSER.DAT\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\NTUSER.DAT’ because it is being used by another process.”,
“2025-06-15 23:24:24 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\ntuser.dat.LOG1\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\ntuser.dat.LOG1’ because it is being used by another process.”,
“2025-06-15 23:24:24 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\ntuser.dat.LOG2\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\ntuser.dat.LOG2’ because it is being used by another process.”,
“2025-06-15 23:24:29 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\lockfile\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\lockfile’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\GPUCache\data_0\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\GPUCache\data_0’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\GPUCache\data_1\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\GPUCache\data_1’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\GPUCache\data_2\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\GPUCache\data_2’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\GPUCache\data_3\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\GPUCache\data_3’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\GPUCache\index\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\GPUCache\index’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\data_0\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\data_0’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\data_1\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\data_1’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\data_2\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\data_2’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\data_3\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\data_3’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\index\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnWebGPUCache\index’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\data_0\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\data_0’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\data_1\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\data_1’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\data_2\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\data_2’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\data_3\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\data_3’ because it is being used by another process.”,
“2025-06-15 23:24:30 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\index\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\Signal\DawnGraphiteCache\index’ because it is being used by another process.”,
“2025-06-15 23:24:38 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileBlockProcessor.FileEntry-PathProcessingFailed]: Failed to process path: C:\Users\jonof\AppData\Roaming\OpenBuildsCONTROL\lockfile\r\nIOException: The process cannot access the file ‘\\?\C:\Users\jonof\AppData\Roaming\OpenBuildsCONTROL\lockfile’ because it is being used by another process.”
],
“Errors”: [
“2025-06-15 23:25:41 -05 - [Error-Duplicati.Library.Main.Operation.BackupHandler-FatalError]: Fatal error\r\nSftpPermissionDeniedException: Permission denied”,
“2025-06-15 23:25:41 -05 - [Error-Duplicati.Library.Main.Controller-FailedOperation]: The operation Backup has failed with error: One or more errors occurred. (Permission denied (Permission denied) (One or more errors occurred. (Permission denied)))\r\nAggregateException: One or more errors occurred. (Permission denied (Permission denied) (One or more errors occurred. (Permission denied)))”
],
“BackendStatistics”: {
“RemoteCalls”: 22,
“BytesUploaded”: 0,
“BytesDownloaded”: 0,
“FilesUploaded”: 0,
“FilesDownloaded”: 0,
“FilesDeleted”: 0,
“FoldersCreated”: 0,
“RetryAttempts”: 20,
“UnknownFileSize”: 628,
“UnknownFileCount”: 3,
“KnownFileCount”: 109705,
“KnownFileSize”: 2835433246565,
“LastBackupDate”: “2025-05-15T04:00:00-05:00”,
“BackupListCount”: 16,
“TotalQuotaSpace”: 0,
“FreeQuotaSpace”: 0,
“AssignedQuotaSpace”: -1,
“ReportedQuotaError”: false,
“ReportedQuotaWarning”: false,
“MainOperation”: “Backup”,
“ParsedResult”: “Success”,
“Interrupted”: false,
“Version”: “2.1.0.5 (2.1.0.5_stable_2025-03-04)”,
“EndTime”: “0001-01-01T00:00:00”,
“BeginTime”: “2025-06-16T04:22:24.658354Z”,
“Duration”: “00:00:00”,
“MessagesActualLength”: 0,
“WarningsActualLength”: 0,
“ErrorsActualLength”: 0,
“Messages”: null,
“Warnings”: null,
“Errors”: null
}
}

This part means that the previous backup failed, and there was a filelist that was never uploaded.

This means that the file was attempted uploaded, but was never stored.

This is the real problem. For some reason, Duplicati is not allowed to write or delete some files on the destination. If the uploads are denied, then it would explain the long list of attempted (and failed) uploads that you see.

Can you check that the user accessing via SFTP has write permissions to the destination folder?