Dimmer Switch simulator issues

I am just getting into Device Type modification, however when I use the standard Dimmer Switch device type in the IDE I am unable to use the simulator. I am able to select the location, and the device and then the right side goes blank. This is using the default code, no changes made whatsoever.

My goal is to change the icon in the main tile to display the dim percentage, as well as add three new tile buttons below with preset dim options.

Is there a github repository of official SmartThings device type’s current source? I think the example of the Dimmer Switch in the IDE is broken.