What causes AADSTS90055?

An application or service principal is hammering the /token endpoint instead of caching and reusing access/refresh tokens. A misconfigured Power BI gateway, ADF linked service, or Databricks job is re-authenticating on every request rather than reusing a token until expiry. The tenant has exceeded Microsoft Entra ID's per-tenant authentication request limits (sign-in throttling). Microsoft has temporarily blocked the tenant due to suspected abuse, compromised credentials, or non-compliant traffic patterns. A retry loop on a different auth error (e.g. AADSTS50076, AADSTS700016) is amplifying request volume and triggering tenant-level throttling

How do I fix AADSTS90055?

Identify the calling application: check Microsoft Entra ID > Sign-in logs, filter on error code 90055, and group by Application and IP to find the source hammering the token endpoint. Stop the offending workload immediately (pause the Power BI dataset refresh schedule, disable the ADF trigger, or stop the Databricks job) so throttling can clear. Implement token caching in the calling code/service: acquire a token once, reuse it until ~5 minutes before expiry, and use the refresh token flow instead of re-running the full client-credentials flow per call. Review retry logic — make sure failures on other AADSTS codes use exponential backoff with jitter, and never retry tighter than every 30 seconds. If sign-in volume looks normal but throttling persists, open a Microsoft support ticket referencing AADSTS90055 and the tenant ID; only Microsoft can lift a tenant-level block

Critical severityauthentication

Power BI Error:
AADSTS90055

What does this error mean?

Microsoft Entra ID (Azure AD) is blocking authentication requests because the tenant is throttled or blocked.

Common causes

1An application or service principal is hammering the /token endpoint instead of caching and reusing access/refresh tokens
2A misconfigured Power BI gateway, ADF linked service, or Databricks job is re-authenticating on every request rather than reusing a token until expiry
3The tenant has exceeded Microsoft Entra ID's per-tenant authentication request limits (sign-in throttling)
4Microsoft has temporarily blocked the tenant due to suspected abuse, compromised credentials, or non-compliant traffic patterns
5A retry loop on a different auth error (e.g. AADSTS50076, AADSTS700016) is amplifying request volume and triggering tenant-level throttling

How to fix it

1Identify the calling application: check Microsoft Entra ID > Sign-in logs, filter on error code 90055, and group by Application and IP to find the source hammering the token endpoint
2Stop the offending workload immediately (pause the Power BI dataset refresh schedule, disable the ADF trigger, or stop the Databricks job) so throttling can clear
3Implement token caching in the calling code/service: acquire a token once, reuse it until ~5 minutes before expiry, and use the refresh token flow instead of re-running the full client-credentials flow per call
4Review retry logic — make sure failures on other AADSTS codes use exponential backoff with jitter, and never retry tighter than every 30 seconds
5If sign-in volume looks normal but throttling persists, open a Microsoft support ticket referencing AADSTS90055 and the tenant ID; only Microsoft can lift a tenant-level block

Frequently asked questions

What does AADSTS90055 mean?

There are too many incoming requests. This exception is thrown for blocked tenants.

How do I fix this error?

Check your application registration, token configuration, and user permissions in the Azure portal. Review Conditional Access policies if the error is policy-related.

Source · learn.microsoft.com/en-us/entra/identity-platform/reference-error-codes#aadsts-error-codes