Exchange 2019 Installation Fails on 89% During Readiness Checks.

During a recent Exchange 2019 deployment I come across an issue where Exchange 2019 setup kept failing on Windows Server 2019 during the readiness checks. The Readiness checks fails on the Web Management Solution Service that fails to start. The post will walk you through some steps on how to resolve this issue.

The error is as follow:

Normally to resolve the above error the following will be done.

1. Open Internet Information Services (IIS Manager)
2. Navigate to “Server Certificates”
3. Create a new “Self-Signed Certificate” and call it “WMSVC”.
4. Next go to “Management Service” In ISS Management
5. Select the newly created self-signed certificate.
6. Click “Apply” and then click on Start.
7. The “Web Management Service” will then start, and you can continue with your installation.

However, during my setup, the above fix did not resolve my issue as the WMSVC certificate was present and valid. I started digging further and had a look at the System event log in Event Viewer and found the following error:

The error indicated some sort of “Access Denied”, so I tried the following.

Launch PowerShell as Administrator and run the following to try and see if the service will start with an elevated console.

Get-Service *WMSVC* |Start-Service

This still resulted in the following “Warning”.

How to resolve?

I tried a few different things to try and get the issues resolve, but the one that resolve my issue was this post: https://techcommunity.microsoft.com/t5/iis-support-blog/wmsvc-web-management-service-failing-to-start-with-quot-access/ba-p/770603

In sort what resolved it was the following.

1. Open Local Group Policy Editor
2. Navigate to Computer > Administrative Templates.
3. Click on System > Mitigation Settings > Untrusted Font blocking.

The “Untrusted Font Blocking” was not configured as per the image below.

To completely resolve my issue, I had to set the “Untrusted Font Blocking” to “Disabled.”

Once the change was applying, restart the server and then launch the Exchange 2019 Installation again.

The setup continues past the 89% on the verification section and then finally allows you to start the install.

Hope this helps the next person and saves some time.

#ThatlazyAdmin

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