26 August 2015 15:28
OK, using the 15.08 SDK preview everything worked fine now. No errors.I'm glad it helped!
Unfortunately, this is a bit unstable at the moment even in the Developer Preview (we are currently working on this feature). So you need to wait stable release.
The developing process would also be described here in the documentation:
https://www.blend4web.com/doc/en/developers.html#sdk (it's a bit outdated by now)