What causes UserErrorFailedBlobFSOperation?

The service principal or managed identity lacks the required RBAC role on the ADLS Gen2 account. The storage account has a hierarchical namespace enabled and the identity lacks the necessary ACL permissions on the directory. The ADLS Gen2 storage account firewall is blocking the integration runtime IP. A transient Azure storage service issue

How do I fix UserErrorFailedBlobFSOperation?

Check the specific BlobFS error code in the ADF activity run output.. Verify the linked service identity has at least Storage Blob Data Contributor (or Reader for reads) on the storage account.. For ADLS Gen2 with hierarchical namespace, also check directory-level ACLs — RBAC alone may not be sufficient.. Review the storage account firewall settings and add the integration runtime IP or VNet if needed.. Add a retry policy to handle transient storage failures.

High severitydata source

Power BI Refresh Error:
UserErrorFailedBlobFSOperation

What does this error mean?

An ADLS Gen2 operation (file read, write, directory creation, or file move) failed during an ADF copy activity due to permission or configuration issues.

Common causes

1The service principal or managed identity lacks the required RBAC role on the ADLS Gen2 account
2The storage account has a hierarchical namespace enabled and the identity lacks the necessary ACL permissions on the directory
3The ADLS Gen2 storage account firewall is blocking the integration runtime IP
4A transient Azure storage service issue

How to fix it

1Check the specific BlobFS error code in the ADF activity run output.
2Verify the linked service identity has at least Storage Blob Data Contributor (or Reader for reads) on the storage account.
3For ADLS Gen2 with hierarchical namespace, also check directory-level ACLs — RBAC alone may not be sufficient.
4Review the storage account firewall settings and add the integration runtime IP or VNet if needed.
5Add a retry policy to handle transient storage failures.

Frequently asked questions

Does this error affect all pipeline runs or just the current one?

Depends on the root cause. A persistent misconfiguration fails every run; a transient issue may resolve on retry. Check the run history.

Can this error appear in Azure Data Factory and Microsoft Fabric pipelines?

Yes — the same connector errors appear in both ADF and Fabric Data Factory pipelines.

How do I see the full error detail for an ADF pipeline failure?

In ADF Monitor, click the failed run, then the failed activity. The detail pane shows the error code, message, and sub-error codes.

Will downstream Power BI datasets be affected when an ADF pipeline fails?

Yes — a dataset refreshing after the pipeline will use stale data or fail if the target table was cleared. The Power BI refresh may succeed while serving wrong data.

Official documentation: https://learn.microsoft.com/en-us/azure/data-factory/connector-troubleshoot-azure-data-lake