Tested on windows 7 using chrome M56 #56.0.2924.87 and issue is not observed.

Steps Followed :

1. Launched chrome and naviagted to given url "https://gmail.google.com/mail/" and didnt observe any shutdown of the url or web page.

Attached screencast for reference.

@marshaul-- Could you please check the issue in a fresh chrome profile without any extensions and flags enabled , and if you can still reproduce the issue , please provide us the screencast of the steps .

Thanks!

Deleted: 694072.mp4 2.2 MB

	694072.mp4 2.2 MB View Download

Yes, the problem persists, which of course it would because it occurs
on *multiple
platforms and fresh installs. *Which facts were clearly articulated in my
bug report.

I am sorry you are unable to duplicate this problem. I note that I
specifically said that this problem does *not* occur in the same build of
Chrome -- it *only occurs in Chromium distributions.* I would suggest that
perhaps the dev team should print more useful messages for debugging,
because right now it seems that you think I'm simply an idiot, whereas I am
not interested in repeating steps I've already taken to prove you wrong.
Useful information would be a convenient way for us to meet in the middle,
but you Chromium fails to provide *any, **at all. *

I am, however, not going to waste my time replicating visually what I
already typed out with semantic and syntactic precision and clarity.

If you believe this is simply user error, then I would suggest that your
judgment on the matter is biased  by dealing with user error too much, for
if you take me at my word, I have performed and described sufficient steps
to preclude that possibility, and frankly every possibility other than a
flaw with Chromium distributions -- albeit one which may only present
itself in limited circumstances.

It is not my responsibility to convince you to do what you need to do.
Either you will, or Chromium will remain broken and I will no longer use
it. That is really all there is to it.

On the other hand, if you would like any *new* information from me, I am
happy to provide what I'm able. Repeating myself to convince you is out of
the question, however.

I can confirm I'm seeing this as well on Windows 10. Same exact problem: the affected sites work as expected in Chrome, but in Chromium, I'm seeing the following:

"This site can’t provide a secure connection

gmail.google.com sent an invalid response.
Try running Windows Network Diagnostics.
ERR_SSL_PROTOCOL_ERROR"

Only certain sites seem to be affected. Perhaps a list of affected/non-affected sites might help with tracking this down?

Affected:
- https://gmail.google.com/mail/
- https://encrypted.google.com/
- https://admin.google.com/
- https://google.com

Not affected:
- https://www.google.com/
- https://www.wikipedia.org/

Affected Chromium version: 56.0.2924.87 (64-bit)

Non-Affected Chrome version: 56.0.2924.87 (64-bit)

Update: I changed the maximum TLS version to 1.2 from the chrome://flags page, as mentioned in this comment:
https://bugs.chromium.org/p/chromium/issues/detail?id=693943#c2

That appears to have stopped the issue from occurring for me.

Are there any network proxies or firewalls running in the network that you're experiencing problems with? Including firewalls that are disabled (we've seen some firewalls/network inspection devices that attempt to parse secure transports even when they are disabled that have caused problems).

Could you also check whether you are getting the same error when visiting: 
https://cert-test.sandbox.google.com

Chrome Stable is shipping a modern, more secure version of the TLS protocol, unfortunately some middle-boxes and network security solutions behave unexpectedly with the new protocol.

You may also be seeing different behaviors between Chromium and Chrome on the same machine due to the rollout for the feature. If you pass "--enable-feature=TLS13Negotiation" as a commandline argument, you should see the same error on both Chrome and Chromium (assuming this is a network issue).

I think this is a duplicate of  issue 693943 .