Cubase ate my preferences again.
Project settings,
Audio connections,
Studio devices,
Key commands and macros.
I honestly just spend hours a week trying to play “catch up” with Cubase and Dorico to get them to work properly.
thanks for doing this, Pls let me know after you got success
If you’re having a bad day and are posting this to let off steam, that’s fine.
But if you want help in figuring out what is going wrong and how to stop it you are going to need to be a lot more descriptive. “Ate” is doing most of the heavy lifting here. 
Opened my template file like I do every morning.
MIDI ports reset
Remotes gone from the Studio device setup
Control room gone
Key commands gone
Project preferences changed
Yes, I am letting off some steam. I’ve been using Cubase (now Nuendo) for 20 years.
In that time Cubase has been screwing up the preference files. I don’t know what needs to be done about it from a programmer’s point of view,
but it seems there are mistakes that go back years that cause unpredictable behavior in the system to overwrite certain preference files in the AppData to (initial) factory settings. I didn’t ask for it. I didn’t do anything that should cause such a thing.
This happens often with Cubase. I was able to fix most of it with backup data, but this is not optimal in any way for a professional workflow.
Even with the backup files I then have to test everything to make sure the remotes are functioning.
I had to manually redo the control room and MIDI port setup.
Stupid things like this grind everything else to a halt. It is a bit tiresome to deal with glitches in “pro” software and at this stage I will remind the programmers every chance I get.
Also, the only way I can see it stopping is if someone at the other end of this software takes the initiative.
There must be some sort of combination that causes this as I’ve never seen this happen on any version of Cubase. I have cleared preferences when updating and setup again and that’s it. They then keep working. Do you back up the preferences so you can put them back in?
It happened to me to many times, especially with 10.5.
It happen too me now and then. It usually are related to communication problem with the audio device so cubase tries to be smart and switch to something else. And it is very confusing, all “global” settings should have a different colour marking and a lock function. And maybe only “connection” configuration. Now you can mix external, controlroom, input and output. Very nice that is and flexible, but it might need one more layer to so you can have all switched. And maybe a association so the “default” is per audio device.
My experience is the same in over 18 years of use. Never had any problem with Preferences, but don’t doubt others are. Suspect mkok is correct that it is some weird combination at the root.
In your post it sounds like repairing your Preferences is taking up a lot of time for each incident. Curious as to why that is? My Preferences are saved as a preset & can be restored in a few moments. If that is also broken it would take a couple of minutes to restore from OS level backups. If it takes you longer than that, what else is happening?