Ok, it's working now.
On server.py file, line 468 there is a for:
"for s in proj_strs:"

For some reason inside "s" variable it's a string "Couldn't find Java", that drives to an error in s.split later inside same for.
After installing JRE problem is gone, but i couldn't find a mention of JRE being a requirement for SDK.
So please mention JRE under System Requirements on web and/or readme file

I reported similar problem here: link
No changes after replacing server.py.

update: sorry, my problem is not related. Also already solved

Seems to be a Linux only issue. Tried on Windows 7, all fine. On another Linux machine, (which runs Debian 8) i get same error:

ERROR:tornado.application:Uncaught exception GET /project/ (::1)
HTTPServerRequest(protocol='http', host='localhost:6687', method='GET', uri='/project/', version='HTTP/1.1', remote_ip='::1', headers={'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.109 Safari/537.36', 'Accept-Language': 'es-419,es;q=0.8,en-US;q=0.6,en;q=0.4,ru;q=0.2', 'Upgrade-Insecure-Requests': '1', 'Connection': 'keep-alive', 'Host': 'localhost:6687', 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8', 'Cache-Control': 'max-age=0', 'Accept-Encoding': 'gzip, deflate, sdch'})
Traceback (most recent call last):
File "/mnt/rojo/SinBack/DevLiveProgs/blend4web_sdk_free/addons/blend4web/lib/tornado/web.py", line 1345, in _execute
result = method(*self.path_args, **self.path_kwargs)
File "/mnt/rojo/SinBack/DevLiveProgs/blend4web_sdk_free/addons/blend4web/server.py", line 560, in get
projects = self.get_proj_list(root, False)
File "/mnt/rojo/SinBack/DevLiveProgs/blend4web_sdk_free/addons/blend4web/server.py", line 470, in get_proj_list
path = s.split("->")[1].strip(" ")
IndexError: list index out of range
ERROR:tornado.access:500 GET /project/ (::1) 1882.56ms

Thanks!

I decompressed zip again, and now it is working fine (pointing to root folder). Must be something with my setup. Thanks!

Steps to reproduce: Press "Project Manager" with running server
In URL: "http://localhost:6687/project/" i get:
500: Internal Server Error

Trace:
——————————————————————-
ERROR:tornado.application:Uncaught exception GET /project/ (::1)
HTTPServerRequest(protocol='http', host='localhost:6687', method='GET', uri='/project/', version='HTTP/1.1', remote_ip='::1', headers={'Connection': 'keep-alive', 'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.21 (KHTML, like Gecko) konqueror/4.14.2 Safari/537.21', 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8', 'Host': 'localhost:6687', 'Accept-Charset': 'utf-8,*;q=0.5', 'Accept-Language': 'en-US,en;q=0.9', 'Referer': 'http://localhost:6687/', 'Accept-Encoding': 'gzip, deflate, x-gzip, x-deflate'})
Traceback (most recent call last):
File "/home/wintch/work/blend4web_sdk_free/addons/blend4web/lib/tornado/web.py", line 1345, in _execute
result = method(*self.path_args, **self.path_kwargs)
File "/home/wintch/work/blend4web_sdk_free/addons/blend4web/server.py", line 560, in get
projects = self.get_proj_list(root, False)
File "/home/wintch/work/blend4web_sdk_free/addons/blend4web/server.py", line 470, in get_proj_list
path = s.split("->")[1].strip(" ")
IndexError: list index out of range
ERROR:tornado.access:500 GET /project/ (::1) 133.00ms
——————————————————————-

Thanks Yuri, could you please check if md5 of blend4web_sdk_free_16_02.zip is d7925bfb57d000daf8edaa386cae3656? This may be the cause to my problem (topic 1659).

Update: Already solved

Really double checked everything. The warning is also asking me to point scripts to sdk root folder, but once that is done, blend4web is not showing anymore (user preferences>add-ons). Blender starts fine, no error messages.
Besides the message, pointing to /blend4web_sdk_free/blender_scripts/ is working fine.

I tried 2.76 version also, and a blender plugin, just not working (no error message).
The only way for me was to point scripts to: /blend4web_sdk_free/blender_scripts/
Now i get a warning:
Deprecated path to scripts. The correct path is….and the message window is too narrow, so can't see the full path

Please take into account:

-blend4web_sdk_free_16_02.zip file is big, MD5 would be great to assure i downloaded it correctly

-Registration captcha is not clear. Needed 5 attempts to register (maybe it's me only?)

-No mention of JRE being a requirement

Thanks!

Hi! Trying to install blend4web gives me this error:

Traceback (most recent call last):
File "/home/user/.steam/steam/steamapps/common/Blender/2.76/scripts/modules/addon_utils.py", line 324, in enable
mod = __import__(module_name)
TypeError: source code string cannot contain null bytes

Import-export: blend4web is on add-ons, but when i try to enable the addon, the above message pops out.
Thanks!

p/s my version is blend4web_sdk_free_16_02