I am getting the same problem too.
My WebCoRE dashboard shows this:
There was a problem loading the dashboard data. The data shown below may be outdated; please log out if this problem persists.
I cannot load any pistons.
The Live logging is repeatedly showing this error for the WebCoRE Instance:
15:30:51: error physicalgraph.api.StatusCodeException: Invalid http status code returned: 401 @line 956 (api_get_base_result)
Ditto. Same problem. Something is afoot me thinks.
@ipaterson @ady624 is the server down or something similar?
Are all of you in the UK? I’m not seeing a problem here on the US SmartThings shard so curious whether this is regional.
The referenced line 956 in the error message seems to be looking up a record of Smart Home Monitor incidents. Would anyone like to try commenting out line 956 of the main webCoRE smart app and publishing the publishing the change to test whether the same error occurs elsewhere?
Change
incidents: hubUID ? [] : location.activeIncidents.collect{[date: it.date.time, title: it.getTitle(), message: it.getMessage(), args: it.getMessageArgs(), sourceType: it.getSourceType()]}.findAll{ it.date >= incidentThreshold },
to the following (just add two slashes at the beginning)
// incidents: hubUID ? [] : location.activeIncidents.collect{[date: it.date.time, title: it.getTitle(), message: it.getMessage(), args: it.getMessageArgs(), sourceType: it.getSourceType()]}.findAll{ it.date >= incidentThreshold },
Tried that. It then says ‘opening piston’ and get the spinning circles. Nothing in logs.
EDIT: What I am not getting now is on the main page, every few seconds it would show a header that there is an issue, if persists, sign out and back in again.
I tried that. It now lets me into the dashboard without the error banner - no errors in the Live Logging.
I was just about to type that opening a Piston does not work but it has opened one after showing the spinning circles for quite a while.
So that appears to have resolved it for me
How long did you wait.
Been 5 minutes for me and still no joy.
Can you still get into your pistons?
probably about 2 minutes. Once one had opened, I am now able to open all the pistons, although I intermittently get:
It is logging this in the LiveLogging:
17:14:07: error physicalgraph.api.StatusCodeException: Invalid http status code returned: 401 @line 5006 (initIncidents)
Everything appears to be working again.
Put line 956 back in play and still working OK.
Them there gremlins have been playing again. 
