Hi,
Sorry about the version mixup.
A few minor things were done in v2.18 with the installer, renaming of the Unity script and MoBu 2016 Beta plugis.
Unfortunately the installer got rolled out with v2.17 of the base application which is why the version check gets things wrong.
I've currently rolled back to v2.17 on the download page since I am running in and out of the hospital for a close family member.
I'll will soon re-release v2.18 correctly.
The 'Synchronize Streams' option indeed can cause problems on some machines when it's switched on at runtime and tries to find a synchronization point.
But actually in practice it wouldn't make any difference to tracking quality anyway.
The body tracker only needs the depth frame so even if the color frame would arrive one frame later or earlier it doesn't affect tracking.
The face tracker does reference the color frame and therefore internally it turns synchronization on at startup.
Actually I thought I removed the button from the Body GUI a while ago but apparently I didn't :)