APIM Standard Central India — intermittent empty HTTP 500 on developer portal homepage and SSO

No public Azure Status incident currently confirms a Central India APIM managed developer portal issue for the stated dates, so enable Developer portal usage resource logs now and use Azure Service Health or Impact Reporting to determine whether Microsoft recognizes a resource-scoped platform event.

Capture managed portal diagnostics

APIM exposes a dedicated DeveloperPortalAuditLogs category for requests processed by the developer portal, including authentication activity, page views, and API test-console activity. Its resource-specific Log Analytics table is APIMDevPortalAuditDiagnosticLog.^1^ ^2^

1. Open Azure portal → API Management service → Monitoring → Diagnostic settings → + Add diagnostic setting.
2. Select the category corresponding to Developer portal usage / DeveloperPortalAuditLogs.
3. Select Send to Log Analytics workspace.
4. Prefer Resource specific destination tables.
5. Save the setting, reproduce / and /signin-sso, and then open Monitoring → Logs.

Start by inspecting the schema rather than assuming columns:

APIMDevPortalAuditDiagnosticLog
| where TimeGenerated > ago(2h)
| take 100

After identifying the URL, status, operation, and correlation fields actually populated in your workspace, filter around the recorded UTC timestamps and compare successful and failed requests. If the diagnostic setting uses Azure Diagnostics mode instead, inspect:

AzureDiagnostics
| where TimeGenerated > ago(2h)
| where ResourceProvider =~ "MICROSOFT.APIMANAGEMENT"
| where Category == "DeveloperPortalAuditLogs"
| take 100

These logs must already have been routed to a destination to investigate historical events. If they were not configured on October 23, the customer-visible evidence for that date is limited to your curl output, browser traces, Service Health history, Activity Log, and any existing monitoring.

Also run APIM service → Diagnose and solve problems, search for Managed Developer Portal, and review Availability and performance and Gateway performance. APIM Diagnostics applies to Standard and is most useful for events within the previous 24 hours, although its graphs remain available afterward.^3^

An API inspector trace is designed to separate inbound, backend, and outbound processing for API calls; it is not the primary diagnostic for the managed portal homepage itself.^4^

Check whether this was a targeted Azure incident

Check Azure portal → Service Health → Health history and filter for:

• Subscription containing this APIM instance
• API Management
• Central India
• October 23–27, 2026
• Service issues and health advisories

The public Azure Status page is reserved mainly for broad incidents. Service Health contains targeted notifications for affected subscriptions, so absence from public status does not exclude a smaller regional, deployment-stamp, or subscription-scoped event.^5^

Resource Health showing Available means no known platform problem was detected for that resource; it does not explain individual intermittent responses. Since your observed availability contradicts that state:

1. Open APIM service → Resource health.
2. Select Report incorrect health status.
3. Include the exact UTC failures, both hostnames, paths, empty 500 response, successful control requests, and business impact.

That reporting option is specifically available when Resource Health says Available but the customer believes otherwise.^6^

As another customer-accessible path, use Service Health → Report an issue → Single resource and provide the impacted APIM resource, start/end time, and business impact. Azure Impact Reporting is currently preview; if Azure identifies an outage, it appears in the portal.^7^

Escalation without a paid plan

A Basic/free plan does not normally include technical support; creating a standard technical case requires a support plan.^8^

Two exceptions may help:

• If Resource Health marks the resource Unavailable because of a platform event, a support request can be opened from Resource Health without a support agreement.^6^
• If Microsoft recognizes this as a service disruption, affected customers can raise a free support ticket for up to 72 hours after mitigation for recovery assistance.^9^

A Q&A moderator can help route or flag the report, but customer-facing Q&A cannot substitute for Microsoft’s service-side telemetry investigation. Provide only non-sensitive details publicly: APIM resource name if acceptable, region, UTC timestamps, response headers or request/correlation IDs, and the Service Health/Impact Reporting result. Do not post subscription or tenant identifiers.

References

1. Monitor API Management
2. API Management monitoring data reference
3. Azure API Management Diagnostics overview
4. Troubleshoot Azure API Management performance issues in API calls
5. Azure Status Overview - Azure Service Health | Microsoft Learn
6. Azure Resource Health FAQ
7. Report an impact (preview)
8. Create an Azure support request
9. What to do during an Azure service disruption