I don't have a proven resolution but I saw this a month ago on v2017.0 Std with S/O Invoice Printing from one workstation (see attached). Upon troubleshooting, we couldn't re-create the issue, so we agreed we just have to wait for it to happen again, ideally with knowing what specific steps may have led to it but it hasn't happened again as far as I know (I wonder if a server and/or workstation reboot did the trick. Or maybe it has to do with the Paperless Office Output selection on the Invoice Printing screen). Just could not figure out what's bringing up that particular prompt/screen (i.e., ""output file name""). It doesn't appear to be caused by selecting PDF or Cute or whatever from the printer drop-down on the Invoice Printing screen. And it does not appear to be related to the Pdf 'prompt' option in Paperless setup.