Hello,
I’ve noticed that the GPUParticles playground referenced in GPU Particles | Babylon.js Documentation is broken. If you prevent GPUParticles via setting var useGPUVersion = true; on line 17 to false the playground works.
Regards
pinging @Evgeni_Popov: do you mind checking?
@Evgeni_Popov is on it 
sorry for the delay
Sorry, missed this one, having a look now.
Will be fixed by:
Great! Thank you