400 - bad_request: File names must not contain '\'


Just installed duplicati and connected it to Backblaze B2, but immediately get this error. I presume it’s from Backblaze:

"Operation Put with file duplicati-20180511T110002Z.dlist.zip.aes attempt 2 of 5 failed with message: 400 - bad_request: File names must not contain '\'
System.Exception: 400 - bad_request: File names must not contain '\'
   at Duplicati.Library.Backend.Backblaze.B2AuthHelper.AttemptParseAndThrowException(Exception ex)
   at Duplicati.Library.JSONWebHelper.GetResponse(AsyncHttpRequest req, Object requestdata)
   at Duplicati.Library.JSONWebHelper.ReadJSONResponse[T](AsyncHttpRequest req, Object requestdata)
   at Duplicati.Library.Backend.Backblaze.B2.Put(String remotename, Stream stream)
   at Duplicati.Library.Main.BackendManager.DoPut(FileEntryItem item)
   at Duplicati.Library.Main.BackendManager.ThreadRun()"

Should I just go hunting for a file with \ in the name or is this something more complicated?


Hi @Beatwolf, welcome to the forum!

Duplicati doesn’t create any file names using a slash (forward or backward) though I suppose it MIGHT be possible to “force” it to by using the --prefix=xxxxxx parameter with a “\” somewhere in xxxxxx. (Note that using --prefix is not recommended as it can cause unnecessary confusion later on.)

A string used to prefix the filenames of the remote volumes, can be used to store multiple backups in the same remote folder. The prefix cannot contain a hyphen (-), but can contain all other characters allowed by the remote storage.
Default value: “duplicati”

I see it’s on attempt 2 of 5, did the backup job quit there or continue on? If it continued, then most likely the next attempt succeeded and there was just something odd about attempt 2.

(By the way, I edited your post by adding “~~~” before and after the error message to make it more readable.)