HTTP error 500 or 403 when accessing VMware Horizon Mirage File Portal or Web Manager

The features File Portal and Web Manager of VMware Horizon Mirage both need Microsoft .NET Framework to work properly. While the File Potal still uses .NET Framework 3.5 SP1 the new Web Manager needs .NET Framework 4.0.

Sometimes if you want to access one of these consoles right after the installation you either get a HTTP 403 error (Web Manager) or HTTP 500 error (File Portal).


Both of these errors most often occure when the relevant .NET Framework version isn’t registered properly with IIS (Internet Information Service).

To solve this issue just run one of the following commands:

Mirage File Portal

C:\Windows\Microsoft.NET\Framework64\v2.0.50727\aspnet_regiis.exe -i

Mirage Web Manager

C:Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -i

These commands register the corresponding .NET version with IIS.

This workaround was only tested on Windows Server 2008 R2 with the 64-bit versions of the Mirage File Portal and Web Manager.

At this point I want to thank my colleague Christian Gehring for pointing out this problem and his help solving it.

Install Horizon Mirage prerequisites via PowerShell

For the installation of the Mirage server components some specific Windows features are needed.

For the Mirage server, the the management server and the management console Microsoft .NET Framework 3.5 SP1 is needed. The installation of this feature can be accomplished via the Server Manager or via PowerShell.

To install .NET Framwork via PowerShell just start PowerShell as an administrator and then run the following two commands:

Import-Module ServerManager
Add-WindowsFeature NET-Framework-Core

To install the Mirage File Portal (WebAccess) also requires .NET Framework 3.5 SP1 but additionally it requires the Microsoft Internet Information Service (IIS) with some additional components like the IIS 6 Management Compatibilit feature.

Source:, Page 44
Source:, Page 44

To install these features through the Server Manager can be a bit cumbersome and using the following PowerShell commands to install IIS and all the features required by the Mirage File Portal is much easier.

Import-Module ServerManager
Add-WindowsFeature Web-Static-Content, Web-Default-Doc, Web-Dir-Browsing, Web-Http-Errors, Web-Asp-Net, Web-Net-Ext, Web-ISAPI-Ext, Web-ISAPI-Filter, Web-Filtering, Web-Mgmt-Console, Web-Scripting-Tools, Web-Mgmt-Service, Web-Metabase, Web-WMI, Web-Lgcy-Scripting, Web-Lgcy-Mgmt-Console

If you haven’t installed .NET Framework before installing IIS just add the NET-Framework-Core at the end of the Add-WindowsFeature command for the IIS feature installation (and don’t forget to add a comma after Web-Lgcy-Mgmt-Console).