Encountered this issue the other day. The report ‘exports’ and the PDF created is 0 bytes (in other words… not exported).
Spent some time Exiting the application and starting it off again, restarting the PC (unfortunately have to use Windows at the office), Uninstaling and Reinstaling Acrobat, and then thinking what else could be causing the conflict. Turns out it was caused by a Windows Update patch.
KB3102429 – That’s the idiotic patch from Windows that caused the issue. Uninstal the patch and everything is back to normal.