My Office Timeline ribbon disappeared from PowerPoint! What can I do?

This issue primarily appears on PowerPoint 2007 and is related to how PowerPoint loads add-ins such as Office Timeline. In order to resolve this issue, follow the steps:

If you have successfully installed Office Timeline but do not see the Office Timeline ribbon inside PowerPoint, follow the steps on this page.  Most ribbon load issues can be solved by trying the following quick fixes in the order listed below:

1. Change add-in Load Settings
On some systems, the default Office behavior for loading add-ins is not set properly.  In this case, you can try resetting the PowerPoint add-in load setting. 
  1. Close all open instances of PowerPoint.
  2. In Windows, click the Start button on the Taskbar > All Programs > Office Timeline and click on Change add-in load settings.
    OfficeTimeLine addin settings
  3. Launch PowerPoint.  If the Office Timeline ribbon is still not visible, try the steps in the next section below (Enable Office Timeline Add-In inside PowerPoint).
2. Enable Office Timeline Add-In inside PowerPoint
It's possible that the Office Timeline ribbon is either disabled or is unable to load due to another Add-In that may be misbehaving.  In this step, check to make sure Office Timeline is not disabled. 
  1. In PowerPoint, click the File tab for PowerPoint 2010 or 2013, or the Microsoft Office button for the PowerPoint 2007

  2. Click the Options button > Add-Ins.
    In the details pane, verify that the add-in does not appear in the Disabled Application Add-ins list.  If it's listed in the Diasabled Applications Add-ins list, enabled it and restart PowerPoint.

  3. If Office Timeline is not listed in the Disabled Add-ins list, click on the Go... button for Manage: COM Add-ins.

  4. In the COM Add-Ins dialog box, make sure Office Timeline 2013 is selected and un-select all other add-ins.  You can re-enable other add-ins later after testing PowerPoint with only the Office Timeline add-in enabled
  5. Click OK and restart PowerPoint.