B4W ERROR: No aspect ratio - Default cube scene

Uncaught engine panic:
The engine tried to perform an invalid operation and halted.

B4W WARN: Canvas size exceeds platform limits, downscaling
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Blend4Web CE version 16.06 - Ubuntu 16.04
Chromium Version 50.0.2661.102 Ubuntu 16.04 (64-bit)

GL_VENDOR NVIDIA Corporation
GL_RENDERER GeForce GT 720M/PCIe/SSE2
GL_VERSION 4.4.0 NVIDIA 340.96

================================================
BROWSER CONSOLE OUTPUT

GL_INVALID_OPERATION : glGenSyncTokenCHROMIUM: fence sync must be flushed before generating sync token
viewer.html:1 WebGL: CONTEXT_LOST_WEBGL: loseContext: context lost
print.js:74 B4W ERROR: WebGL context losterror @ print.js:74
print.js:112 B4W WARN: Canvas size exceeds platform limits, downscaling
print.js:74 B4W ERROR: No aspect ratioerror @ print.js:74
util.js:2104 Uncaught 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/
print.js:112 B4W WARN: Canvas size exceeds platform limits, downscaling
print.js:74 B4W ERROR: No aspect ratioerror @ print.js:74
util.js:2104 Uncaught 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/

================================================
BASH CONSOLE OUTPUT

Read new prefs: /home/brettk/.config/blender/2.77/config/userpref.blend
found bundled python: /home/brettk/Tools/blender-2.77a/2.77/python
serving at port 6687
Scene saved to /home/brettk/Tools/blend4web_sdk_16.06/tmp/preview/preview.json
EXPORT OK
Created new window in existing browser session.
Scene saved to /home/brettk/Tools/blend4web_sdk_16.06/tmp/preview/preview.json
EXPORT OK
Created new window in existing browser session.
Created new window in existing browser session.
WARNING:tornado.access:404 GET /index_assets/favicon.ico (::1) 0.79ms
WARNING:tornado.access:404 GET /favicon.ico (::1) 0.80ms
[7992:8058:0630/194652:ERROR:gcm_store_impl.cc(306)] Failed to open database /home/brettk/.config/chromium/Default/GCM Store: Invalid argument: /home/brettk/.config/chromium/Default/GCM Store: does not exist (create_if_missing is false)
[7992:8058:0630/194652:ERROR:gcm_store_impl.cc(306)] Failed to open database /home/brettk/.config/chromium/Default/GCM Store: Invalid argument: /home/brettk/.config/chromium/Default/GCM Store: does not exist (create_if_missing is false)
WARNING:tornado.access:404 GET /index_assets/favicon.ico (::1) 1.00ms
WARNING:tornado.access:404 GET /favicon.ico (::1) 0.82ms
Scene saved to /home/brettk/Tools/blend4web_sdk_16.06/tmp/preview/preview.json
EXPORT OK
Created new window in existing browser session.
../../sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc:**CRASHING**:seccomp-bpf failure in syscall 0099
Received signal 11 SEGV_MAPERR 000002c20063
#0 0x7f929aaa639e base::debug::StackTrace::StackTrace()
#1 0x7f929aaa678b <unknown>
#2 0x7f928463b3d0 <unknown>
#3 0x7f928ddb0453 sandbox::CrashSIGSYS_Handler()
#4 0x7f928dfc1697 sandbox::Trap::SigSys()
#5 0x7f928463b3d0 <unknown>
#6 0x7f9284368487 sysinfo
#7 0x7f928436642e get_phys_pages
#8 0x7f928432ea60 __sysconf
#9 0x7f928429a6ae qsort_r
#10 0x7f9273ae03bb <unknown>
#11 0x7f9273ae667a <unknown>
#12 0x7f9273be6208 <unknown>
#13 0x7f9273db5bc9 <unknown>
#14 0x7f9273dc9db7 <unknown>
#15 0x7f927433750b <unknown>
#16 0x7f9274339c6e <unknown>
#17 0x7f92744cb176 <unknown>
#18 0x7f92744ceab2 <unknown>
#19 0x7f92743711e5 <unknown>
#20 0x7f9274371562 <unknown>
#21 0x7f92743715f8 <unknown>
#22 0x7f92744cb796 <unknown>
#23 0x7f92744d81d4 <unknown>
#24 0x7f927407c876 <unknown>
#25 0x7f927407cbf8 <unknown>
#26 0x7f927407ce28 <unknown>
#27 0x7f92744ddde3 <unknown>
#28 0x7f9273ff3da1 <unknown>
#29 0x7f9292c58f51 <unknown>
#30 0x7f9292c597bc <unknown>
#31 0x7f9292c59867 <unknown>
#32 0x7f9292c5a012 <unknown>
#33 0x7f9292c5a1ed <unknown>
#34 0x7f9292c74da2 <unknown>
#35 0x7f9292c27b3a gpu::CommandParser::ProcessCommands()
#36 0x7f9292c89b9a gpu::GpuScheduler::PutChanged()
#37 0x7f929670e58e <unknown>
#38 0x7f9296713370 <unknown>
#39 0x7f9292029437 IPC::MessageRouter::RouteMessage()
#40 0x7f929670c0a5 content::GpuChannel::HandleMessageHelper()
#41 0x7f929670c14e content::GpuChannel::HandleMessage()
#42 0x7f929670a28c <unknown>
#43 0x7f929aaa7fb9 base::debug::TaskAnnotator::RunTask()
#44 0x7f929aaca51c base::MessageLoop::RunTask()
#45 0x7f929aacad0d base::MessageLoop::DeferOrRunPendingTask()
#46 0x7f929aacafd9 base::MessageLoop::DoWork()
#47 0x7f929aa96f19 base::MessagePumpGlib::HandleDispatch()
#48 0x7f929aa96f5d <unknown>
#49 0x7f92865bb1a7 g_main_context_dispatch
#50 0x7f92865bb400 <unknown>
#51 0x7f92865bb4ac g_main_context_iteration
#52 0x7f929aa96c6a base::MessagePumpGlib::Run()
#53 0x7f929aae7298 base::RunLoop::Run()
#54 0x7f929aac9745 base::MessageLoop::Run()
#55 0x7f929674167f <unknown>
#56 0x7f929620f1c4 <unknown>
#57 0x7f929620e5f1 content::ContentMain()
#58 0x560c1888529a <unknown>
#59 0x7f9284281830 __libc_start_main
#60 0x560c18885159 <unknown>
r8: 00007ffd4225007c r9: 0000000000000001 r10: 0000178dc7e98820 r11: 0000000000000000
r12: 00007ffd42250080 r13: 0000178dc23ed400 r14: 00007ffd422500c0 r15: 0000178dc3171d80
di: 0000000000000001 si: 00007f928ddb3079 bp: 00007ffd422500c0 bx: 0000000002c20063
dx: 0000000000020000 ax: 0000000002c20000 cx: 00007f928463a4fd sp: 00007ffd42250080
ip: 00007f928ddb0453 efl: 0000000000010206 cgf: 0000000000000033 erf: 0000000000000006
trp: 000000000000000e msk: 0000000000000000 cr2: 0000000002c20063
[end of stack trace]
[7992:7992:0630/194706:ERROR:gpu_process_transport_factory.cc(655)] Lost UI shared context.

Thanks for the bug report!

Looks like this is related to this Chromium sandbox bug with the latest Ubuntu Release.
Drivers update can possibly help. Anyway, we'll try to find some workaround for such setup.

I'll try with the –disable-gpu-sandbox flag as suggested: https://bugs.chromium.org/p/chromium/issues/detail?id=615651#c7

Either way, I'll let you know.

That would be very helpful because we do not have any PC with such GPU to test at the moment.

Using the –disable-gpu-sandbox command line parameter fixes the issue: previewing a scene in Chrome works without any apparent issues (as before).

Thanks,

Brett