I found when the problem occurs. I had same issue when i had installed any othe than 2012 SQLServer LocalDB. I had installed SQLServer Express 2017 with localdb support then i uninstalled LogalDB then I be able to install onyx.
I think this is the onyx bug.
I you have installed Onyx and then you install SQLServer LocalDB component you will not be able to load show.
I hope guys will fix the issue quickly because I’ve another software on my laptop which needs to have another version LocalDB