Found 87 parse-able files with the prefix <dest-path-name>/duplicati, did you forget to set the backup prefix?

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1

Just upgraded Duplicati to latest stable (2.2.0.1) on Ubuntu. Everything works, but database was out of sync.

So I renamed the local database and started a recreate. Recreate fails immediately with the following error:

2025-12-02 16:53:10 +01 - [Error-Duplicati.Library.Main.Controller-FailedOperation]: The operation Repair has failed\nUserInformationException: Found 87 parse-able files with the prefix path/to/Duplicati/Destination%20Folder/duplicati, did you forget to set the backup prefix?"

Backup files are stored in “/path/to/Duplicati/Destination%20Folder” using WebDAV(S). Test Destination returns “Connection tested successfully”.

Somehow Duplicati seems to append the destination path to the prefix, which aborts recreation of the local database.

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2

Found the solution myself. The destination folder (WebDAV) contained spaces. Spaces are automatically URL-encoded (i.e. target folder is converted to target%20folder), but the database repair/recreation process does not parse these folder names correctly and treats the full path as the prefix for remote volumes.

I guess this is a bug that should be fixed in a future version.

3

Not sure how this could happen… The parser should only see the filenames, the folder names should have been stripped for any operation that involves the database.

I think this is related to the recent fix to extend WebDAV parsing perhaps?
If you can still reproduce this? If so, can you try to set --use-legacy-parsing in the advanced options before clicking “Test connection” ?

Yes, it should be possible to use folder paths with spaces.

4

I was able to reproduce this. Performed the following actions:

  • Deleted local database and started a DB recreate. Result: DB successfully recreated.
  • Deleted local database again, inserted spaces in backend folder name and started DB recreate. Result: DB recreated failed immediately with error message “did you forget to set the backup prefix”.
  • Deleted (empty) local database, set -use-legacy-parsing to True in Advanced options, started DB recreate (with spaces still in backend folder name). Result: DB successfully recreated.

So it looks like the new parsing of WebDAV folder names is failing when it contains one or more spaces.

5

I have the same problem since the last stable update. But my webdav path has no spaces.

On old backups I became:
[Error-Duplicati.Library.Main.Controller-FailedOperation]: The operation Backup has failed
RemoteListVerificationException: Found 1124 files that are missing from the remote storage, and no files with the backup prefix duplicati, but found the following backup prefixes: DuplicatiPC/E/duplicati

On another backup I test “repair” and “delete and repair”, but after this still not working again.
Than I delete the backup folder and create a complete new backup and now I became this error:
Found 293 parse-able files with the prefix DuplicatiPC/C/duplicati, did you forget to set the backup prefix?

Now I have activate the “legacy-parsing” to “true” and all is fine :slight_smile: