Creating Image system.log error

Hello! I’m a new Winclone user. Running winclone 7.3.4 on Mac OS High Sierra 10.13.6. The external hard drive I’m saving the image to is in ExFAT. Winclone seems to freeze at “Archiving data”. The system.log for Winclone says:

Dec 28 20:14:33 Bonnies-iMac Winclone[613]: assertion failed: 17G10021: libxpc.dylib + 75013 [7B82608D-ED82-35C1-B13F-99855E25D6DC]: 0x89
Dec 28 20:14:52 Bonnies-iMac Winclone[613]: BUG in libdispatch client: kevent[mach_recv] monitored resource vanished before the source cancel handler was invoked

I noticed that when I click “Save Image” the bootcamp unmounts (as seen in Disk Utility). I’m not running any other anti-virus and time machine is not running. Any suggestions? Thank you!

I got it to work by formatting the partition to Mac OS Extended (Journaled) not ExFAT.