Tried your recommendation but still coming up with that error
Yeah...there's a lot of coding errors in this app. I wouldn't recommend using it till those get addressed by the author.
@napalmcsr, the child app you linked to in the first post isn't savable in Hubitat as it has several coding errors. Could you either take down the app or fix the errors to avoid other users running into this same problem? Thanks!
See post 23
Please see post 23.
Yeah....that's the version I used. The one in your github. It doesn't work. Either take it down or update it or fix it please. If not, I'll request the thread be locked and the links removed. The app doesn't work.
reading is for others 
please see first post...
Why what,? I deleted like you asked and updated post 1 to point to post 23, fixed per what you asked...
The link in post #1 goes to nothing.
as it should go nowhere as the fix is in post 23?
See post 23. It shows how to do this in rule machine.
Why not put the correct link in Post #1 rather than make people hunt for post by a number?!?! You're just being really difficult about something that everyone else just does. It's just common courtesy.
That's post 24 actually, see why you should just use a direct link to the post rather than using a number.
nope, most people can look down a line, but I'll go fix it
It's still NOT post 23, which was all you kept barking at me being completely unhelpful.
but I'll go fix it
Future tense, someone as exact as you should understand that 
@napalmcsr I believe the sample rule you posted is what I'm looking for but as I'm new to building these type of rules in Hubitat I'm confused how you actually set-up the "actions to run" Could you possibly provide screen shots of how you coded setTemperature(%MBR-Temperature%) on Thermostat: MBR.
What I want to achieve is I've set-up a virtual thermostat that I want to set my actual thermostat temp to match the temp set in the virtual thermostat. I've searched all over hubitats docs and this forum but I can't seem to find examples how to actually code this in Rule Machine 4.0 only the end result like you have posted but missing the steps to get there.
Thanks,
Chris
You need to create a local variable, mine was MBR_Temperature, I don't use RM anymore so adding the steps would be difficult.
Thanks @napalmcsr Now I need to learn how to create local variables and then how to reference them in an action.
