What causes External Table Metadata Refresh Error?

The cloud storage location (S3 bucket, Azure Blob container, or GCS bucket) is no longer accessible — storage account key or IAM role expired. The storage integration used by the External Table lacks the necessary read permissions on the storage location. The Event Grid, SNS, or Pub/Sub notification integration is broken and automatic refresh events are not firing. The external files were deleted or reorganized, invalidating the previously cached file paths

How do I fix External Table Metadata Refresh Error?

Manually trigger a metadata refresh: `ALTER EXTERNAL TABLE REFRESH`.. If the refresh fails, check the external stage credentials: `DESCRIBE STAGE ` and verify the storage integration or credentials are still valid.. For event-driven refresh, check the notification integration: `DESCRIBE NOTIFICATION INTEGRATION ` and verify it is enabled and the cloud event subscription is active.. Confirm the Snowflake storage integration IAM role still has `s3:GetObject`, `s3:ListBucket` (or equivalent) on the bucket.. After fixing the underlying access issue, run `ALTER EXTERNAL TABLE REFRESH` to resync metadata.

Medium severitydata source

Power BI Refresh Error:
External Table Metadata Refresh Error

What does this error mean?

Snowflake could not refresh the metadata for an External Table. The metadata cache is out of sync with the underlying cloud storage, and queries may return stale or incorrect results.

Common causes

1The cloud storage location (S3 bucket, Azure Blob container, or GCS bucket) is no longer accessible — storage account key or IAM role expired
2The storage integration used by the External Table lacks the necessary read permissions on the storage location
3The Event Grid, SNS, or Pub/Sub notification integration is broken and automatic refresh events are not firing
4The external files were deleted or reorganized, invalidating the previously cached file paths

How to fix it

1Manually trigger a metadata refresh: `ALTER EXTERNAL TABLE <table> REFRESH`.
2If the refresh fails, check the external stage credentials: `DESCRIBE STAGE <stage_name>` and verify the storage integration or credentials are still valid.
3For event-driven refresh, check the notification integration: `DESCRIBE NOTIFICATION INTEGRATION <integration_name>` and verify it is enabled and the cloud event subscription is active.
4Confirm the Snowflake storage integration IAM role still has `s3:GetObject`, `s3:ListBucket` (or equivalent) on the bucket.
5After fixing the underlying access issue, run `ALTER EXTERNAL TABLE <table> REFRESH` to resync metadata.

Frequently asked questions

What is the difference between auto-refresh and manual refresh for External Tables?

Auto-refresh uses cloud event notifications (SNS/Event Grid/Pub/Sub) to trigger metadata sync when new files arrive. Manual refresh (ALTER EXTERNAL TABLE REFRESH) must be run explicitly or on a schedule via a Snowflake task.