Virtual Appliance — Downgrade Virtual Hardware Version 19

TranslationThe pending.openthinclient Virtual Appliance ships for VMware with a specific VM hardware version. The current version uses VM version 19. Earlier VMware environments might require a compatible version. In this case, downgrade the VM version to import the appliance. This article describes how to adjust the VM version in the .ovffile of the appliance.

Prerequisites:

Download the openthinclient Virtual Appliance (ZIP file)

An extraction tool, e.g., 7-Zip, WinRAR

A text editor that supports UTF-8 and large files, e.g. Notepad++, VS Code

Target version of the VM hardware supported by the VMware environment, e.g., vmx-13 for ESXi 6.5

Step-by-step instructions:

Extract the ZIP archive — Extract the downloaded ZIP file of the virtual appliance to a local directory.

Open the OVF file — In the extracted directory,
locate the file named openthinclient-Appliance-[VERSION].ovf (example: openthinclient-Appliance-2025.2.2.ovf) and
open it with a suitable text editor.

Find VM version — Search the file for the following XML entry:

<vssd:VirtualSystemType>vmx-19</vssd:VirtualSystemType>

Adjust the version — Replace vmx-19 with the version supported by the VMware environment, e.g.:

<vssd:VirtualSystemType>vmx-13</vssd:VirtualSystemType>

Note: Refer to the VMware documentation for an overview of VM hardware compatibility.

Import the modified OVF — Save the file and import the virtual appliance via the vSphere Client or VMware Workstation.

Important notes:

Create backups — Retain a copy of the original ZIP file before modifying it.

Backward compatibility — When downgrading, ensure that the target version supports the required hardware features, e.g., newer CPU or device features.

Performance — The VM generally continues to run stably, and it may benefit from further optimizations in the newer hardware version.