Create troubleshooting guide for PublicAccessNotPermitted error (#11777)

* Create troubleshooting guide for PublicAccessNotPermitted error

Added troubleshooting guide for PublicAccessNotPermitted error in Azure Blob storage, including symptoms, causes, and resolutions.

* Add troubleshooting section for PublicAccessNotPermitted error

* Modify section headers for access options

Updated section headers for clarity regarding access options.

Author: jeffpatt24

support/azure/azure-storage/blobs/authentication/storage-troubleshoot-publicaccessnotpermitted-error.md

@@ -0,0 +1,50 @@
+---
+title: Troubleshoot PublicAccessNotPermitted error
+description: How to troubleshoot PublicAccessNotPermitted error.
+ms.date: 06/23/2026
+ms.service: azure-blob-storage
+author: jeffpatt24
+ms.author: jeffpatt
+ms.custom: sap:Authentication and Authorization
+---
+
+# Troubleshoot PublicAccessNotPermitted error
+
+When accessing Azure Blob storage, you may encounter a `PublicAccessNotPermitted` error. This article describes how to resolve this error.
+
+## Symptom
+
+When attempting to access an Azure Blob container or blob, you may receive the following error:
+
+```text
+Public access is not permitted on this storage account.
+ErrorCode: PublicAccessNotPermitted
+```
+
+## Cause
+
+This error occurs when an unauthenticated (anonymous) request is made to a blob or container that does not allow public access.
+
+## Resolution
+
+#### Option 1: Use authenticated access (recommended)
+
+Instead of enabling anonymous access, use a supported authentication method to securely access Azure Blob storage:
+
+- **Microsoft Entra ID (recommended)**  
+  [Authorize Blob Access with Microsoft Entra ID](/azure/storage/blobs/authorize-access-azure-active-directory)
+
+- **Shared access signature (SAS)**  
+  [Grant limited access to data with shared access signatures (SAS)](/azure/storage/common/storage-sas-overview)
+
+- **Storage account key**  
+  [Authorize with Shared Key](/rest/api/storageservices/authorize-with-shared-key)
+
+For more information: [Authorize access to data in Azure Storage](/azure/storage/common/authorize-data-access)
+
+#### Option 2: Enable anonymous access (only if required)
+
+> [!WARNING]
+> When a container is configured for anonymous access, any client can read data in that container. This can introduce significant security risks. Only enable anonymous access when explicitly required.
+
+If your scenario requires anonymous access, see: [Configure anonymous read access for containers and blobs](/azure/storage/blobs/anonymous-read-access-configure)

support/azure/azure-storage/blobs/toc.yml

@@ -20,6 +20,8 @@
   items:
   - name: Troubleshoot portal access issues
     href: authentication/storage-troubleshoot-portal-access-issues.md
+  - name: Troubleshoot PublicAccessNotPermitted error
+    href: authentication/storage-troubleshoot-publicaccessnotpermitted-error.md
   - name: Troubleshoot 403 errors
     href: authentication/storage-troubleshoot-403-errors.md
   - name: Sticky bit causes 403 authorization error