Descriptive Problem Summary:
When attempting to join a game through WebClient, DreamDaemon rejects the connection with the following error message: BYOND Error: failed to certify (null) from ip ****** origin ******:2000

Looking at the browser's logs I see a failed Post request to byond.com

Request URL: http://www.byond.com/
Request Method: POST
Status Code: 503 Service Temporarily Unavailable
Remote Address: 104.24.100.180:80
command: keyreq
url: http://****:2000

Looking at the Response Body it contains the following:

"Checking your browser before accessing byond.com.
This process is automatic. Your browser will redirect to your requested content shortly.Please allow up to 5 seconds."

I assume that CloudFare's ddos protection is blocking the request for a key.

Numbered Steps to Reproduce Problem:
Make an empty game, host and connect through the web client.

OR connect to:

http://www.byond.com/play/13.59.53.132:2000

Expected Results:
The game should load even with client/authenticate set to 0.
Actual Results:
The connection is forefully ended by Dream Daemon.
Does the problem occur:
Every time? Or how often?
Every time. (Web client is unusable)
-Edit-
The Http Post error doesn't always happen but DD closes the connection regardless. Note that there is the following message also: Version: 512, 498

Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? (Visit http://www.byond.com/download/build to download old versions for testing.)
I've tested over 8 versions and none work.