Hello.
Gladly for you, you completely messed up the process, that’s why it’s failing.
I’m saying “gladly” because Car Play should work on 3.0, and we had some cases that upgrading to 3.4 didn’t solve that either.
So, first things first: you need to ensure Car Play works on 3.0.
You need to install 2.2.17011 first, to see if CP is activated. Take this message (and thread) as reference → 2016 Mustang Sync3 1.0 updated to 3.0 and no Apple Carplay! - #10 by SaNdMaN
Once CP works, you can go to 3.4 if you still desire so by simply configuring Syn3updater correctly.
this is where you messed it up, you are not on 3.4 right?.
Lucky error.