Scenario

In order to find the installed version of Unity's Vivox SDK plugin for Unreal Engine (VivoxCore) which is being used in your Unreal project, complete the following steps.

Resolution

1. Open the Unreal Editor.
2. In the top menu bar, select Edit > Plugins.
3. Search for "Vivox", and use the left side panel to select the plugin category called Installed. In older Unreal Engine versions, the Installed section is instead called Project.
4. Find the Vivox Core Unreal plugin published by Unity/Mercer Road Corp. The plugin version will appear in the upper right corner.

Note: Do not confuse this plugin with any found in the Built-In plugin category published by Epic Games. This is a deprecated version of Vivox which used to be included in Unreal Engine versions 4.22 through 4.26.
Note: The plugin version listed might differ from what is shown in the example image.