Azure Blob Storage error – Issues interacting with Azure Blob Storage in Power Automate

Power Automate allows users to interact with Azure Blob Storage to upload, download, delete, and manage files. However, sometimes Azure Blob Storage errors occur due to authentication failures, incorrect file paths, API limits, or permission issues.

This guide provides:
Common causes of Azure Blob Storage errors
Step-by-step troubleshooting solutions
Best practices to prevent future errors

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Step 1: Identify the Azure Blob Storage Error

1.1. Check Flow Run History

1. Open Power Automate → My Flows.
2. Click on the failing flow → Go to Run History.
3. Locate the Azure Blob Storage action and check the error message.

Common Azure Blob Storage error messages:

• “Authentication failed”
• “Permission denied”
• “File not found”
• “Invalid file format”
• “Container does not exist”
• “Rate limit exceeded”

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Step 2: Fixing Common Azure Blob Storage Errors

2.1. Invalid Azure Storage Connection

Problem: The Azure Blob Storage connection in Power Automate is invalid, expired, or missing.

Solution:

• Go to Power Automate → Data → Connections.
• Find Azure Blob Storage and check its status.
• If marked as “Invalid”, click Fix Connection or Re-authenticate.
• If the issue persists, remove and re-add the Azure connection.

Tip: Ensure you are using the correct Azure Storage Account Name and Access Key.

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2.2. Insufficient Permissions on Blob Storage

Problem: The flow user lacks the necessary permissions to access or modify blobs.

Solution:

1. In Azure Portal, go to Storage Account → Access Control (IAM).
2. Assign the “Storage Blob Data Contributor” role to the user or service principal.
3. If using Azure AD authentication, ensure the user has RBAC (Role-Based Access Control) permissions.

Tip: If using a SAS token or Shared Key, ensure they haven’t expired.

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2.3. Incorrect Blob Container or File Path

Problem: The flow is trying to access a nonexistent container or file.

Solution:

• In Azure Portal → Storage Explorer, verify the container name.
• Ensure the blob path (including folders) is correct.
• In Power Automate, use dynamic content to reference the correct file path.

Tip: Azure Blob Storage paths are case-sensitive. Ensure the names match exactly.

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2.4. File Not Found or Deleted

Problem: The flow is trying to access a file that does not exist or has been deleted.

Solution:

• Use the “List blobs” action before retrieving a file to verify its existence.
• Add a Condition to check if the file exists before proceeding with other actions.
• If the file was deleted, restore it from Soft Delete (if enabled).

Tip: Azure supports Soft Delete for blobs—enable it in Azure Portal → Data Protection.

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2.5. Invalid File Format or Corrupt File

Problem: The flow is trying to process a file format not supported or the file is corrupt.

Solution:

• Verify the file format is supported by Power Automate.
• If working with JSON or XML, validate the file using an online parser.
• If the file is corrupt, try uploading a new version.

Tip: Convert unsupported formats before processing using Azure Functions or Logic Apps.

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2.6. API Rate Limit Exceeded

Problem: The flow is making too many requests to Azure Blob Storage in a short period.

Solution:

• Add a “Delay” action between storage operations.
• Reduce the number of “Get blob content” or “List blobs” actions per flow run.
• Implement batch processing for bulk operations.

Tip: Azure imposes throttling limits based on storage account SKU and region.

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2.7. Storage Account Firewall or Network Restrictions

Problem: The Azure Storage Account has firewall rules blocking access from Power Automate.

Solution:

1. In Azure Portal → Storage Account → Networking, check Firewalls and virtual networks settings.
2. If using a Private Endpoint, ensure Power Automate can access it.
3. Allow your public IP address if necessary.

Tip: If Power Automate needs to connect from anywhere, set “Allow public access” in networking settings.

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Step 3: Preventing Future Azure Blob Storage Errors

✅ 3.1. Use Managed Identities for Secure Authentication

• Instead of SAS tokens or Shared Keys, use Azure Managed Identity for secure access.
• Assign the Storage Blob Data Contributor role to the Managed Identity.

✅ 3.2. Implement Error Handling in Power Automate

• Wrap Azure actions inside a “Scope” action and configure error handling.
• Use “Run after” settings to retry failed actions automatically.

✅ 3.3. Optimize API Calls to Avoid Throttling

• Use batch operations instead of individual file requests.
• Avoid unnecessary “Get blob content” calls.

✅ 3.4. Validate File Existence Before Processing

• Use “List blobs” or “Check file existence” before performing actions.
• Add a Condition to ensure the file exists.

✅ 3.5. Monitor Storage Performance Regularly

• Enable Azure Monitor to track storage activity and API limits.
• Set up alerts for high API usage or unauthorized access attempts.

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