18:00 GMT, 30/10/2018:
This issue is now resolved. All users should be able to access DSM as usual.
12:00 PM GMT, 30/10/2018:
A server side certificate issue was discovered and this is currently being addressed with the highest priority.
The next update will be later this afternoon.
14:00 GMT, 29/10/2018:
We have received reports of users unable to login to the latest beta version of DSM. This is currently being investigated.
More updates to follow.