Unable to drag PDF documents from Outlook to In Tray

Hi,

I used to be able to drag and drop outlook PDF files into my purhcases Intray but for some reason when I perform the same action now, there will be a loading cursor that appears and the program hangs for about a few seconds then nothing happens and the file has not been transferred into my Intray. I normally export alot of purchases invoices via outlook so hoping to get some help to get this function working again.

Thank you.

Ken