Unable to create a NetBoot image on Sierra

I've been trying for a couple of ways in every way imaginable to create a Netboot image for sierra. Up until now I've tried doing the following: - Mounting the disk from a vm and using that as source - Using the Install Sierra.app as source - Using a tool like autoNBI - Doing the whole workflow through the automator But when using the disk image utility it always gives error 2 after the "Creating cache" step. Any clues? Creating a netrestore image is no problem by the way.. I tried running the commandline tool imagetool instead. It gave me a very similar error. Here is the complete output: imagetool --netboot --index 2000 --source /Volumes/Macintosh\ HD\ 2 --destination '/Users/Styleshoots/Desktop/netboot\ images/' --name 'sierra netboot' 2016-11-01 14:20:46.182 imagetool[788:13710] Imaging failed. Error: Error Domain=System Image Utility Code=2 "(null)" 2016-11-01 14:20:46.596 imagetool[788:9044] imaging tool has completed '/Users/Styleshoots/Desktop/netboot\ images.nbi' 2016-11-01 14:20:46.596 imagetool[788:9044] image creation took 536.859359 seconds.