Reply to post of user Konstantin Khomyakov
Thanks for the report!

This is really a bug which appears because export options "Export Vertex Animation" and "Apply Modifiers" are mutually exclusive. We'll try to fix this issue

Reply to post of user Will Welker
So you already had the subsurf modifier and you just hit the 'Apply' button?
Glad it was and easy fix.

Reply to post of user Will Welker
Ok, I am getting the problem you describe.
This error repeats continually in the console:

B4W ERROR: missing data for "a_tbn_next" attribute  Tes.html:325:577
uncaught exception: engine panic:
The engine tried to perform an invalid operation and halted.
Please copy the console contents above and submit it to the Blend4Web forum at
https://www.blend4web.com/en/forums/forum/17/  (unknown)
B4W ERROR: missing data for "a_tbn_next" attribute  Tes.html:325:577

We will need to wait for one of the developers to explore this issue.
I can confirm the problem lies with the baked animation. The project loads when this is removed.

Reply to post of user Will Welker
Well, that narrows it down. The bake animation is huge and it loads fine without it.
Are you able to replicate the problem with smaller bake animations?
Any console errors showing up?