# "The stream does not support concurrent IO read or write operations"

**URL:** <https://forum.duplicati.com/t/the-stream-does-not-support-concurrent-io-read-or-write-operations/16929>\
**Category:** Support\
**Created:** [October 25, 2023, 4:18pm UTC](https://forum.duplicati.com/t/the-stream-does-not-support-concurrent-io-read-or-write-operations/16929 "2023-10-25T16:18:53Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![hippalectryon-0](https://forum.duplicati.com/user_avatar/forum.duplicati.com/hippalectryon-0/32/8580_2.png) [@hippalectryon-0](https://forum.duplicati.com/u/hippalectryon-0)\
**Post date:** [October 25, 2023, 4:18pm UTC](https://forum.duplicati.com/t/the-stream-does-not-support-concurrent-io-read-or-write-operations/16929/1 "2023-10-25T16:18:53Z")

</div>

My problem:  
On a brand new install of Duplicati Beta (2.0.7.1) on Windows 10, I setup a new backup. The backup location is a Scaleway (s3-like) bucket. The connections works fine.  
When I attempt to sync, it fails with this error:

```plaintext
System.AggregateException: One or more errors occurred.
---> System.AggregateException: The stream does not support concurrent IO read or write operations.
---> System.NotSupportedException: The stream does not support concurrent IO read or write operations.
...

```

Reading the links below I changed `s3-ext-signatureversion` but this didn’t fix the problem.

Probably related:

> [@The stream does not support concurrent IO read or write operations](https://forum.duplicati.com/t/the-stream-does-not-support-concurrent-io-read-or-write-operations/2218):
>
> I have Duplicati working on one of my machines, but the other Windows 2016 Server has the following error everytime the job runs from a schedule. Failed: The stream does not support concurrent IO read or write operations. Details: System.NotSupportedException: The stream does not support concurrent IO read or write operations. at Duplicati.Library.Main.BackendManager.WaitForComplete(LocalDatabase db, IDbTransaction transation) at Duplicati.Library.Main.Operation.BackupHandler.Run(String[] so…

> [@S3 Compatible Storage - The stream does not support concurrent IO read or write operations](https://forum.duplicati.com/t/s3-compatible-storage-the-stream-does-not-support-concurrent-io-read-or-write-operations/14003):
>
> Im trying to setup a Backup Job with a S3 compatible Storage, the connection is working fine but the upload fails with the following error: Other posts with the same error had no solution, but it seems to be a S3 specific issue. Duplicati Version is 2.0.6.3. Any ideas? Febr. 2022 11:30: Failed while executing “Backup” with id: 6 System.AggregateException: One or more errors occurred. —\> System.AggregateException: The stream does not support concurrent IO read or write operations. —\> System…

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<div class="post-metadata">

**Author:** ![hippalectryon-0](https://forum.duplicati.com/user_avatar/forum.duplicati.com/hippalectryon-0/32/8580_2.png) [@hippalectryon-0](https://forum.duplicati.com/u/hippalectryon-0)\
**Post date:** [October 25, 2023, 5:04pm UTC](https://forum.duplicati.com/t/the-stream-does-not-support-concurrent-io-read-or-write-operations/16929/2 "2023-10-25T17:04:00Z")

</div>

This problem got solved by following [Backup Duplicati to scaleway.com](https://forum.duplicati.com/t/backup-duplicati-to-scaleway-com/11019) and adding the setting `s3-ext-authenticationregion=fr-par`