Hi @sprytax @ptax255 , the issue "Cannot create a file when that file already exists", has been resolved in latest version of ProSeries, but if the issue still persists, I would recommend you to delete the temp files.

To delete the temp files press WINDOWS + R, it'll open run dialog. Type %temp% and press enter. This opens the 'Temporary Files' or 'Temp' folder. Sort by Type and delete all the files with type BAK File.

Then from Proseries try to send the checklist again, it should word.