Tried plugins one by one - removing them one at a time until I got them to be able to work. With everlight, you can't use the UI button to turn the furnaces on.

I've noticed this as well. Any chance of the plugin getting an update?

I have added this in the recent update

hello, ive updated the plugin but still not work for electric furnace...

if unload Everlight, it work.

    "Electric Furnace": {
      "Enabled": false,
      "Use permission": false,
      "Permission": "everlight.electricfurnace.deployed"
    },​

You need to have it enabled and use permissions id you only what one certain groups to have it 

Merged post

Not sure if there is a conflict with server light and quick smelt I'll have a look I to it