DocumentationExperience Cloud KCS

‘Connection Failed’ error during AEM Content Transfer Tool extraction key validation

Last update: October 31, 2026

This article explains how to troubleshoot and resolve the Connection Failed error that can occur when validating the extraction key in the Adobe Experience Manager (AEM) Content Transfer Tool during migrations from on-premises AEM to AEM as a Cloud Service.

Description description

Environment

  • Adobe Experience Manager (AEM) on-premises (all supported versions)
  • AEM as a Cloud Service (all versions)

Issue/Symptoms

  • Extraction key validation fails when creating a migration set in the Content Transfer Tool UI.
  • The network response shows validationSuccess: false and an error message containing Connection Failed.

Cause

This error usually indicates that the on-premises AEM Author server cannot reach the required storage endpoint used by AEM as a Cloud Service, often due to network, firewall, or proxy restrictions.

Resolution resolution

To fix the Connection Failed error, follow these steps:

  1. Validate network connectivity from the on-premises AEM Author server to the storage endpoint used by AEM as a Cloud Service. The specific endpoint URL can be found in your migration set details or Adobe documentation.

  2. Open a command prompt or PowerShell on the on-premises AEM Author server and run a TCP connectivity test to the storage endpoint on port 443. For example:

    • PowerShell: Test-NetConnection -ComputerName <storage-endpoint-hostname> -Port 443 -InformationLevel Detailed
    • Confirm that the result shows TcpTestSucceeded : True.

  3. Test HTTPS/TLS connectivity to the storage endpoint:

    • Command: curl.exe -v -o NUL -D - https://<storage-endpoint-hostname>/
    • Ensure that the connection is successful and no TLS/SSL errors are reported.

  4. Check firewall and proxy settings to ensure outbound connections from the on-premises AEM Author server to the storage endpoint on port 443 are allowed. If outbound traffic is restricted to proxy-only, coordinate with your network team to allow direct or proxied access as required.

  5. After confirming network connectivity, retry the extraction key validation process in the Content Transfer Tool UI.

  6. If the issue persists, collect relevant error.log and access.log entries from the on-premises AEM Author server during the failed validation attempt for further troubleshooting.

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