I am using the DocumentUltimate trial version , on the demo Overview , When I upload whatever .ppt or .pptx file and the documentViewer alert the message:

ERRO

The type initializer for '_XfD' threw an exception  
---> The type initializer for '_mPD' threw an exception  
---> The type initializer for '_mPD' threw an exception  
---> The type initializer for '_zGD' threw an exception  
---> The type initializer for '_zGD' threw an exception  
---> The type initializer for '_qaD' threw an exception  
---> The type initializer for '_qaD' threw an exception  
---> object not reference to an instance.

but i tried online Demo,it works fine.

 

I am sure the version is latest version of DocumentUltimate.