can't open pdf outlook 2013

We Can’t Open … It’s possible the file is already open, or you don’t have permission to open it – Outlook 2013 when opening PDF
2.5 (15)

Issue You are trying to open a PDF file in Outlook 2013 and are presented with the following error message: Microsoft Outlook – We can’t open ‘C\Users\%user%\AppData\Local\Microsoft\...