After selecting the source folder, destination folder, and date range, I got the following error message after I clicked on Run:
System(-2147219956): Exception formatting data:({0}:failed copy[{1}] messages[{2}] witch code [0x{3:X8}])
It didn't matter if it was running as an Outlook plugin or as a stand-alone app. I got the same error message time and time again. The app will work on some folders but not on everything.