The same issue also happened on my PC.
I purchased Tabs for Word and Tabs for PowerPoint (not Office Tab).
I installed both programs in order of Word and PowerPoint. In this case, Tabs for PowerPoint was worked but Tabs for Word did not work.
In the next step, I tried to reinstall Tabs for Word. As a result, Tabs for Word was worked and Tabs for PowerPoint did not work.
Both programs seemed to comflict with each other.
I need your help. How can I fix it?
OS: Windows10 64 bit
Office: Office Professional 2013