When you attempt to open an add-in file, and the add-in is not loaded because of macro security, PowerPoint temporarily stores (caches) the failure-to-load information about this add-in.
This behavior can occur if the following conditions are true: PowerPoint couldn't load the add-in file name. The add-in is listed as an available add-in in the Add-Ins dialog box, but the check box is not selected, and you receive an error message similar to the following when you attempt to select the check box: When you lower the level of macro security in Microsoft PowerPoint, and then open a PowerPoint add-in file (*.ppa), the new level of macro security may not be applied, and the add-in file may not run as expected. For more information about this change, read this blog post.
Office 365 ProPlus is being renamed to Microsoft 365 Apps for enterprise.
