SMB destination fails with existing Duplicati repository containing ~20,000 files ("Not enough credits")

Support
1

I’m running Duplicati 2.2.0.3_stable_2026-01-06. I have several backups tasks that were imported and were running successfully from version 2.1.0.5 using the File destination type.

With some help writing this post with ChatGPT, here is the story.

Today, I modified one of my backup sources and saved the task. After that change, the backup was no longer working. I discovered that the destination path previously configured under the File destination was no longer available, and no matter how I tried to re-enter the path, Duplicati could not reconnect to the NAS share.

While troubleshooting, I found that Duplicati now has a dedicated SMB destination type. I configured it and initially it appeared to work for a simple task. So, I started migrating my other backup tasks (about 10 jobs) from File to SMB, but I encountered a problem.

For existing backup folders (and already working task), using the SMB destination the connection test fails with:

Error listing content: Not enough credits

I tried different configurations:

  • hostname vs IP address
  • different path formats
  • verifying permissions
  • testing with new folders

During testing, I discovered an important detail:

  • Existing Duplicati repository folder (~20,000 files) → fails
  • Newly created empty folder under the same share → works

The repository contains normal Duplicati backup files:

  • .dblock.zip.aes
  • .dindex.zip
  • .dlist.zip

The total repository size is approximately 944 GB, with a dblock size of 100 MB.

This leads me to believe that the issue is related to directory enumeration in the SMB destination backend. It appears that the SMB backend cannot properly list a directory containing a large number of files, while the previous File destination worked correctly.

My questions:

  1. Is the SMB destination currently known to have issues with large directories?
  2. Is there an SMB parameter, timeout, or credit limit that can be adjusted?

I’m a little bit nervous now because, I have no way to add new folders to any of my tasks because as soon as I save them, they become broken…

Thanks in advance for your help!

--
David

2

Well, by reversing to the old UI I was able to reconfigure and reconnect everything correclty. My issue is gone.

But there is still two issues I think:

  1. The new interface is broken (unable to insert network path manually for the File destination
  2. The SMB destination seems to also be broken were there is more than a specific amount of file in the folder (>20k?)

Thank you!