Addressed UUF #441976

Added a new error code to address WI - https://dev.azure.com/msft-skilling/Content/_workitems/edit/441976

Author: AbhishekMallick-MS

articles/backup/troubleshoot-azure-files.md

@@ -2,7 +2,7 @@
 title: Troubleshoot Azure Files backup
 description: This article is troubleshooting information about issues occurring when protecting your Azure Files.
 ms.service: azure-backup
-ms.date: 04/30/2025
+ms.date: 08/11/2025
 ms.topic: troubleshooting
 author: AbhishekMallick-MS
 ms.author: v-mallicka
@@ -307,6 +307,13 @@ Recommended Actions: Ensure that the following configurations in the storage acc
 
 **Recommended action**: The next backup will be automatically triggered with increased vault storage.
 
+### UserErrorStorageKeyBasedAuthenticationNotPermitted
+
+**Error code**: `UserErrorStorageKeyBasedAuthenticationNotPermitted`
+
+**Error message**: Storage account does not support key based authentication required for Azure Backup integration.
+
+**Recommended action**: Enable storage key based authentication on storage account and the retry opertaion.
 
 ## Common policy modification errors