issue enabling Federation Trust, error: A special Rpc error occurs on server ECHO101: Access is denied.

Hello, @Angel Canales

Welcome to the Microsoft Q&A platform!

The error message "A special Rpc error occurs on server ECHO101: Access is denied." suggests that there might be a permissions issue or a configuration problem.

One of the more common causes of Hybrid Configuration Wizard (HCW) failures is the Federation Trust step for the Exchange on-premises organizations in Full hybrid configurations. Federation trust is a mandatory step in the on-premises Exchange organizations when configuring Full hybrid deployments with Exchange Server 2010 coexistence.

If there is no problem with your permissions and the version of the software. You can follow the steps below to troubleshoot in depth:

1.Run the following command on the on-premises Hybrid server to check for valid certificates:

Get-ExchangeCertificate | where { ($_.CertificateDomains -eq 'Federation') -and ($_.Status -eq 'Valid')} | Select-Object -Expand Thumbprint

2.If the command fails, you might need to create a new certificate or reconfigure the existing one.

3.Manually run the failing command from the HCW log with the Verbose switch to get more details on the error and the serialized remote exception.

For detailed steps on address Federation Trust issues, you can refer to the official Microsoft documentation: https://techcommunity.microsoft.com/blog/exchange/how-to-address-federation-trust-issues-in-hybrid-configuration-wizard-hcw/1144285.

Also, for detailed steps on configuring federated trust, please click on https://learn.microsoft.com/en-us/exchange/configure-a-federation-trust-exchange-2013-help for reference.

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Thank you for your support and understanding.

Best Wishes,

Alex Zhang