We are occasionally running into an odd bug that I'm wondering if anyone else has experience and if so, what to do about it. We are using Simplify 3D with the FlashForge Creator Pro. On some files, the print path will print random layers of filament where there are void (empty) spaces. One example is all but 2 of the files on this Thingiverse thing
http://www.thingiverse.com/thing:662447/#comments. If you go to the comment section, the thread started by "wonka" and commented on by "Jeggo", you can see where other people running S3D and FFCP are having the same trouble with it. I've experimented with various settings and nothing makes it go away. To double check it, if I set the External Fill Pattern to either rectilinear or concentric it prints the void area. Thank you for any suggestions/help!