I have a 2 TB Fusion Drive in a 5K iMac (Late 2015). Two days ago, I started the bootcamp assistant to create a partition for Windows 10. It got stuck (let it run 30 minutes), however, which forced me to reboot the machine. After booting, I lost 164 GB from my Fusion Drive.
I googled and found a solution, which states to boot into recovery and run diskutil cs resizeStack <LGVID> 0g, which I did. However, I am not able to let it resize, because it immediately throws an error. Following the error does not work either.
I also tried repairing the disk with Disk Utility which runs for a few minutes, then says everything's fine. Nothing changed of course.
Output of gpt -r show /dev/disk0:

Output of diskutil verifyDisk disk0:

What can I do now?

diskutil verifyDisk diskXwith X=disk identifier of the two disk building the drive - in your case either 0 or 1 (check the physical volumes in your screenshot). – klanomath Feb 03 '16 at 11:32diskutil cs resizeStack 25FF.... 2126gor slightly smaller like 2125500m) – klanomath Feb 03 '16 at 11:37gpt -r show /dev/disk0– klanomath Feb 03 '16 at 11:40repairDisk. Just appended two screenshots with the outputs. – bluefirex Feb 03 '16 at 12:17resizeStackwith a value that is not 0g. Still complains about incorrect size. – bluefirex Feb 03 '16 at 16:12