web.py is not working on browser below firefox 44

I am trying to use web.py and in my firefox 44, everything is working great. But I then tried other versions, I have tried firefox version 14, 16,20+,30+, all are not display well. But firefox 44 and above are working fine.

I have no idea how to investigate this and could not find information in google. Does anyone know what was going on here? Thanks a lot!