Hybrid Configuration Wizard fails to run – manifest download error on all machines

Hello,

I am unable to run the Exchange Hybrid Configuration Wizard (HCW) for our Exchange 2016 environment. The issue occurs on multiple machines and networks, so it does not appear to be a local configuration problem.

Environment:

Exchange Server: 2016 CU23

Windows versions tested: Windows Server 2016, Windows 10 (all fully updated)

.NET Framework: 4.8 (Release 528040 / 4.8.03761)

TLS: TLS 1.2 enabled, SSL 3.0/TLS 1.0/1.1 disabled

Network: No proxy, firewall, or other network restrictions; internet access available

Problem:

When attempting to run HCW via https://aka.ms/HybridWizard, the wizard fails to start.

I have also tried to run HCW offline by downloading Microsoft.Online.CSE.Hybrid.Client.application, but it immediately fails.

The error log shows the following repeated messages:

Downloading file:///C:/Users/.../Application Files/Microsoft.Online.CSE.Hybrid.Client_17_1_3902_0/Microsoft.Online.CSE.Hybrid.Client.exe.manifest did not succeed.
Could not find a part of the path 'C:\Users\...\Application Files\Microsoft.Online.CSE.Hybrid.Client_17_1_3902_0\Microsoft.Online.CSE.Hybrid.Client.exe.manifest'

This occurs on all tested machines (three PCs across three different networks).

ClickOnce cache has been cleared, root certificates are up-to-date, .NET is 4.8, and TLS 1.2 is active.

Attempts to resolve:

Ensured TLS 1.2 is enabled and default in .NET and OS

Verified .NET 4.8 installation

Cleared ClickOnce cache (rundll32 dfshim CleanOnlineAppCache)

Updated root certificates

Tried multiple machines and networks

Tried to run offline using .application file and local copy of Application Files

Result:

HCW fails immediately with DeploymentDownloadException / DirectoryNotFoundException for the manifest.

The issue is reproducible on all tested machines.

Request:

Please advise if there is an official offline installation method for HCW or a way to obtain a working manifest.

If this is a temporary issue with the hosted distribution, please confirm expected resolution or workaround.

Thank you for your assistance.