Updated to v.0.12.8
Fixed various, but most importantly the preload feature should be working nicely, as well as issues with broken images paths in the topbar (as noted by @dxodik).
Also, there is now an optional download without the content folder, which is not necessary for updating. Use the same link as before, but change x3.latest.zip to x3.latest.nocontent.zip. Keep in mind, once the official release is out, I would recommend getting the updated sample content also.
Updating
Just a note on updating, as this should be quite simple now! After downloading latest release, just drag over all files except the /content/ folder and /config/ folder. All your settings are kept intact!