Simulator not simulating! WebSocket is already in CLOSING or CLOSED state

I’m just getting started with the development of my own SmartApps and really like the simplicity and speed of integration. However, I’m finding that the simulator doesn’t function half the time.

I’ve just created a small app which uses a couple of presence sensors and a motion detector. When I fire up the simulator there are no code/syntax errors and I’m asked to pick my virtual devices via the preferences. When I then click install I’m presented with the three sensors but they do nothing. I can change the drop down but when I hit the ‘play’ button nothing happens. Looking in the Chrome dev tools, every time I hit the button I’m getting a WebSocket error:

WebSocket is already in CLOSING or CLOSED state.

But even closing the page or refreshing it makes no difference.

Has anyone seen this before and know what the problem is?

I’m using the latest version of Chrome


I’m also seeing the samething, i saw somwhere that you need a port opened, but why is non of this inside the Docs?? As a fresh developer jumping into the smartthings IDE I must say it’s not easy, theres bugs everywhere, hitting 500 errors from browsing templates. the page is not responsive, simulators doesn’t work, temperature celsius fahrenheit unit wont switch. I’ve only started reading the docs yesterday and I wonder how much more hurdles I need to get over, before I can write an app.