After a successful install, the Office Timeline tab (also known as the Office Timeline ribbon) is missing from PowerPoint.
Typically, when the Office Timeline ribbon does not appear in PowerPoint (or disappears from PowerPoint), the cause is related to one of these three things:
Office Timeline becomes disabled or is conflicting with other add-ins.
PowerPoint requires elevated privileges to run Office Timeline.
Office Timeline needs to be installed with correct permissions.
Please try the following steps (A, B, C) in this order:
A) Make sure Office Timeline is enabled and not conflicting with other add-ins:
Open PowerPoint, click File (or the Office button), click Options, and choose Add-Ins on the PowerPoint Options dialog box that opens.
In the details pane, check to see if Office Timeline appears in the Disabled Application Add-ins list.
If the tool is listed in Disabled Application Add-ins...
You will need to enable Office Timeline by selecting Disabled Items from the Manage drop-down list and pressing Go.
Then, select Office Timeline from the list of disabled add-ins and press the Enable button.
Select COM Add-ins in the Manage drop-down list and press Go.
In the COM Add-Ins dialog box, check Office Timeline and un-check all other add-ins (you can re-enable them one at a time later).
Click OK. PowerPoint will add Office Timeline to the ribbon.
If solution A above does not work, try solution B next:
B) Run PowerPoint with elevated privileges.
NOTE: This is a critical step to try.
Following the steps in the Run PowerPoint with Elevated Privileges article can solve the problem in many cases.
If solution B above does not work, try solution C next:
C) Install Office Timeline with Elevated Permissions
Uninstall Office Timeline. In Windows, navigate to the Control Panel > Programs and Features and uninstall Office Timeline.
Add your user account to the local machine Administrator Group by following these steps.
Download and install the latest build of Office Timeline from https://www.officetimeline.com/updates.
Open PowerPoint and test Office Timeline.
Close PowerPoint and repeat step 4 to test if the add-in is staying functional.
Remove User account from Admin group.