New source browser experience hanging

I enabled the New Source Browser Experience. When I go to view the source code, I can drill down thru our directories and see the files in a folder with 178 files. However, whenever I try to access a folder with 495 files, the working circle icon just spins. It has been spinning for more than 20 minutes. I get the same results in both IE and Chrome. I have also tried it in multiple of our Mercurial repositories.