There is an interesting article involving the ERR_SPDY_PROTOCOL_ERROR messages that I found recently: <a href="http://techdows.com/2015/08/fix-chromes-err_spdy_p" rel="nofollow">http://techdows.com/2015/08/fix-chromes-err_spdy_p</a>... The thing that interests me the most is that it could be related to Avast's Web Shield. I have recently added exclusions for the Roll20 addresses, hopefully this will prevent the problem, because it is very frustrating when this happens. Essentially you need to stop all Chrome processes (including googledrivesync (if present)) and restart them, sometimes this doesn't even work.