Resolve CloudFront 403 and 503 errors on AEM Stage after maintenance

Last update: October 15, 2026

CloudFront 403 and 503 errors can occur on Adobe Experience Manager (AEM) Stage environments after scheduled maintenance due to duplicate or conflicting monitoring configurations. This article explains how to identify and resolve the configuration conflict.

Description description

Environment

Adobe Experience Manager (AEM) Stage environment

Issue/Symptoms

After scheduled maintenance and a restart of platform services, public endpoints become unavailable and return CloudFront errors such as HTTP 403 or 503.
Direct requests to Apache/Dispatcher and AEM from within the environment return HTTP 200 responses, indicating that local services are running.

Cause

Multiple monitoring configurations or agents are enabled at the same time, causing a configuration conflict that prevents AEM services from starting completely.

Resolution resolution

Follow the steps to resolve the issue:

Review the AEM startup logs for errors or warnings related to monitoring agents or configuration conflicts.
Check the Stage environment configuration for duplicate or conflicting monitoring agent entries.
Remove or disable duplicate or conflicting monitoring configurations so that only one monitoring agent is active.
Restart the affected platform and AEM services to allow the system to complete its startup sequence.
Verify that AEM services start successfully and that public endpoints are accessible without CloudFront errors. Public requests should return HTTP 200 responses.

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