Secure connection failed

When attempting to use any roll20 site, I receive a "secure connection failed" error in Firefox and a "ERR_CONNECTION_CLOSED" in chrome. I was able to use roll20 a few months ago, but now can't. 

OS- mac 10.7.5
browser - chrome 49.0.2623.112  Firefox 48.0.2
all extensions disabled
cache and cookies cleared
dns flushed
antivirus - avast 12.8

Firefox gives no log
chrome gives this log:

https://roll20.net/compendium/dnd5e/BookIndex net::ERR_CONNECTION_CLOSED
https://roll20.net/compendium/dnd5e/BookIndex:1 GET https://roll20.net/compendium/dnd5e/BookIndex net::ERR_CONNECTION_CLOSED
https://roll20.net/compendium/dnd5e/BookIndex:1 GET https://roll20.net/compendium/dnd5e/BookIndex net::ERR_CONNECTION_CLOSED

Currently posting from mobile network on my phone seems to be working

Drespar said:

Just to clarify, are you completely unable to use the site or do you simply recieve these errors in the console log but can otherwise use the site?

Completely unable to use the site on my computer.

My wife is having the same problem on her computer. I am not. We both are using OS X 10.11.6, Firefox 55.0.3, but the error occurs for her with Chrome and Safari as well.

Firefox is not providing me with a console log (that is, the log is blank).

The error page says:

The connection to roll20.net was interrupted while the page was loading.

The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
Please contact the website owners to inform them of this problem.

Chrome provides a similar error log to what Despite posted initially:
GET https://roll20.net/ net::ERR_CONNECTION_CLOSED

Safari only shows: Failed to open page https://roll20.net

Basically what Isaac said, no console log is provided other than what I posted.