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429 throttling and empty environment lists

429 Too Many Requests

What you see

A scan stalls or fails, and the log shows 429 Too Many Requests responses from the Power Platform APIs.

Why it happens

Power Platform throttles tenants that send too many requests in a short window. Large tenants hit this most often when a scan walks every environment and downloads every flow definition.

What to do

The app already retries throttled and server-error responses with exponential backoff (Polly, up to 3 retries per call), so a short throttle window usually resolves on its own. The current retry policy does not read the Retry-After header, so on a busy tenant the retries can still exhaust.

If 429s persist:

  1. Re-run the audit later, outside peak hours for your tenant.
  2. Scan fewer environments at once instead of the whole tenant; see Running an audit.
  3. If you run your own settings file, you can tune the retry knobs. Discovery calls use PowerPlatform:RetryPolicy:MaxRetries and PowerPlatform:RetryPolicy:DelaySeconds; flow downloads use Scan:MaxRetryCount and Scan:RetryBaseDelaySeconds. Increase the base delay rather than the retry count (retry counts are clamped to 3). Keys and defaults are in the configuration reference.

The environment dropdown is empty

What you see

Flow Auditor opens, but the environment dropdown contains nothing.

Why it happens

Environments are listed from https://api.bap.microsoft.com; flow definitions come from https://api.flow.microsoft.com, and each endpoint needs its own token. If the BAP endpoint is unreachable, or the identity cannot read it, the list comes back empty.

What to do

  1. Confirm the account or service principal has the Power Platform Admin role; without it the list is legitimately empty. See API permissions.
  2. Check that the machine can reach https://api.bap.microsoft.com. A corporate proxy or firewall that allows only login.microsoftonline.com and api.flow.microsoft.com will block environment discovery. Allow both API hosts.
  3. Look at the status text under the dropdown: a failed load shows the underlying error message there.

If it still fails

Search the newest log in %APPDATA%\PowerToolBox\logs for the failing host name; see Find logs and diagnostic data. If sign-in itself is failing, work through Sign-in errors 401 and 403 first. Then open a ticket on the support page with the log excerpt and the correlation ID if a dialog showed one.

Last updated: July 27, 2026