Unable to Save As in Acrobat

I have this strange problem. I have installed the Acrobat Standard DC (version 2015.006.30121) and have also successfully activated it using the provided product ID. When I want to save an Acrobat document to another name or location, by selecting File->Save As..., I got a blank popup as seen below. I have tried uninstalling and re-installing and it is still the same. Can somebody help?