After a successful installation of the add-in, the Office Timeline ribbon (also known as the Office Timeline tab) is not functional inside PowerPoint.
If the Office Timeline ribbon in PowerPoint is grayed out, you may need to update Visual Studio 2010 Tools for Office on your machine. Office Timeline relies on two Microsoft components in order to function properly:
Visual Studio 2010 Tools for Office Runtime (VSTO)
.NET Framework 4.8
During installation, Office Timeline will check to see whether a current version of VSTO is already installed. If your existing version of VSTO is not current, Office Timeline will try to update it for you before proceeding to install itself. This process sometimes gets blocked on PCs where users don’t have administrative privileges or where corporate policy has restricted a user’s privileges.
Any installation errors that reference VSTO, such as: file:///C:Program Files (x86)/Office Timeline/2014/OfficeTimeline.vsto or VSTOR40\vstor40_x86.exe, are likely caused by an issue related to VSTO.
Uninstall the existing version of Office Timeline, download and install the latest version of VSTO from Microsoft, and then download and install the latest version of Office Timeline. Following these steps will typically resolve this issue.
Close all open instances of PowerPoint.
Uninstall Office Timeline. In Windows, navigate to the Control Panel > Programs and Features and uninstall Office Timeline.
Download and install Visual Studio 2010 Tools for Office Runtime (VSTO Version 10.0.60724) from Microsoft at https://www.microsoft.com/en-us/download/details.aspx?id=48217.
NOTE: You may need administrative privileges to install this component.
Download and install the most current version of Office Timeline from: https://www.officetimeline.com/updates
Once the latest version of Office Timeline has been installed, click on the Office Timeline tab in PowerPoint and confirm it is functioning properly.