I am experiencing the same issue. I have tried Chrome 64.0.3282.186 and Firefox 52.6.0 ESR.
With Firefox, this intermittently works - I have tried on two different PCs (running the same browsers) and experienced the same issue. Out of the box Windows 10 configurations too!
I tried with cache disabled as suggested above, but this didn’t work.
There is a problem here which needs some attention - happy to provide any logs etc. if required.