Lost all Scene elements with 2019.2 upgrade

Greetings,
I had a project, thankfully just something I was building with my kids, that I'd put together in 2018.3. I upgraded to 2019.2 today, and...it's all gone. The files still exist (scripts, images, etc.) but the scene has none of the objects. There's a Main Camera, and...nothing else. Everything's in the Assets folders, but it's not together.

I'm just...aghast.

My kids wanted to work on it, and I made some excuses, and I'll have to spend a few hours putting back together what we'd built. I've had this happen before; for example, I've never managed to get Unity on their computers to load a git clone of a Unity project and have the objects in place. But I thought that was just some file I was missing that must not be in the project tree. This is on the same computer, same files, just a different version.

Sure; I didn't have it in version control, which was my fault. I didn't expect an upgrade of Unity to...I don't even know...wipe my Scene out entirely?

Has anyone ever had any luck getting it back, when that happens? What should I look for? How do I keep it from happening again?

-- Morgan

 

Greetings,
Oh. A bit more searching, and I bet I know what happened.

It appears that Unity will overwrite Scenes with the same name (or same GUID?) without prompting, if you import a package that has that scene.

The Scene we were building was probably under 'SampleScene', since that automatically exists when starting up, and when upgrading the assets, Unity probably re-imported whatever provides SampleScene, and because it had the same name or GUID, it overwrote my scene.

That's...pretty awful.

That's a terrible, terrible bug.

-- Morgan

[Edit: I wonder if that's why my attempts at cloning simple projects to my kids computers haven't worked; the Unity editor on the far end overwrites my scene, because I'm new at this, and put everything in SampleScene to start with.]

 

Unity doesn't re-generate the sample scene ever. There's probably something else funky going on.

Making git work with Unity is pretty straight-forward:
- Set the project to "use visible meta files"
- Use a .gitignore to ignore the Library/ and Temp/ folders (you'd usually just copy one)
- That's it.

To open the project on a different computer, just clone it into a new folder and select "Add" in the Hub menu. I guess what you're describing could happen if you try to make a new project in the location you cloned to.

 

Greetings,
That's fair; I've tried to replicate that sequence on another computer (creating a project in one rev, adding some stuff to the sample scene, loading it in another) and it doesn't fail obviously. I really don't know, and I'm tired and frustrated. I've got it mostly back to where I was.

I was hoping very much that it was that as a problem, because then it's understandable and avoidable. It seemed that the SampleScene.unity file was (after the project was upgraded to 2019.2) dated some time in 2018, when I'd created it a few days ago.

If it's not that, then...there's no way to know when a Unity upgrade is just going to eat my scene. Which...sure, it means version control is absolutely required, which is a best practice anyway, but that's still...pretty awful uncertainty. I'm just frustrated, right now, and I was hoping it was something straightforward, because the signs pointed that way.

-- Morgan