Error on backup. Log shows a duplicate file, but its only a single file on the server?

Support
1

Hello,

since a few days I have encountered an error on one of my duplicati 2 (2.0.4.5_beta_2018-11-28) backup jobs.

This is the message:

Found remote files reported as duplicates, either the backend module is broken or you need to manually remove the extra copies. The following files were found multiple times: duplicati-b633c12e9400c44b5b3135ea1a889ee88.dblock.zip.aes

The Remote-Log lists all files.
The mentioned file is listed twice in the log. But on the ftp server I see only one single file with this name!
Repair and Verify Files from GUI does not fix the problem.

…
{“Name”:“duplicati-ib192217e750549aca9b0f98a2d884330.dindex.zip.aes”,“LastAccess”:“2017-07-14T00:48:51+02:00”,“LastModification”:“2017-07-14T00:48:51+02:00”,“Size”:18429,“IsFolder”:false},
{“Name”:“duplicati-b633c12e9400c44b5b3135ea1a889ee88.dblock.zip.aes”,“LastAccess”:“2019-09-11T15:13:03+02:00”,“LastModification”:“2019-09-11T15:13:13+02:00”,“Size”:52342477,“IsFolder”:false},
{“Name”:“duplicati-b633c12e9400c44b5b3135ea1a889ee88.dblock.zip.aes”,“LastAccess”:“2019-09-11T15:13:03+02:00”,“LastModification”:“2019-09-11T15:13:13+02:00”,“Size”:52342477,“IsFolder”:false},
{“Name”:“duplicati-b4c6ccec36c334a799999416dad86c16a.dblock.zip.aes”,“LastAccess”:“2018-06-20T14:31:45+02:00”,“LastModification”:“2018-06-20T14:31:47+02:00”,“Size”:52342477,“IsFolder”:false},
…

How can I proceed to fix this issue?

2

OK. Problem solved.

Just for anybody that has a similar Problem.
I’m using a Fritzbox with a USB drive and a smb share for the backup. German users will know the router brand.
The integrated smb server has trouble with to many files in one folder (in this case over 22k) and sometimes lists more or less files. This must be considered as a bug.
I switched to FTP for accessing the drive and the problem with duplicate file listings disappeared.