What causes UserErrorRestApiCallFailed?

The API returned HTTP 401 (unauthorized) — bearer token, API key, or OAuth credentials are invalid or expired. The API returned HTTP 404 — the endpoint URL in the linked service or relative URL is incorrect. The API returned HTTP 429 — the calling rate exceeds the API's rate limit. The API returned HTTP 500 — a server-side error on the target API

How do I fix UserErrorRestApiCallFailed?

Check the error message for the HTTP status code and response body.. For 401: refresh the authentication token, API key, or OAuth credentials in the ADF linked service.. For 404: verify the endpoint URL is correct and the resource path exists.. For 429: add a retry policy to the Web activity with exponential backoff.. For 500: the error is server-side — check the target API's status page and retry after the issue resolves.

High severitydata source

Power BI Refresh Error:
UserErrorRestApiCallFailed

What does this error mean?

An Azure Data Factory Web activity or REST copy source/sink failed because the target REST API returned a non-success HTTP status code. The error carries the HTTP status code and response body from the target API.

Common causes

1The API returned HTTP 401 (unauthorized) — bearer token, API key, or OAuth credentials are invalid or expired
2The API returned HTTP 404 — the endpoint URL in the linked service or relative URL is incorrect
3The API returned HTTP 429 — the calling rate exceeds the API's rate limit
4The API returned HTTP 500 — a server-side error on the target API

How to fix it

1Check the error message for the HTTP status code and response body.
2For 401: refresh the authentication token, API key, or OAuth credentials in the ADF linked service.
3For 404: verify the endpoint URL is correct and the resource path exists.
4For 429: add a retry policy to the Web activity with exponential backoff.
5For 500: the error is server-side — check the target API's status page and retry after the issue resolves.

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-rest