Downgrading project from 2019 to 2018...easiest way?

I know there's a bunch of issues when downgrading projects. But my current project in 2019.1 is mainly just a bunch of art assets and some lighting. I need this project to be downgraded to 2018.3. I tried to open it in 2018, but I got some errors and my assets don't show up in my scenes.

What's the best way to do this? Do I need to rebuild my whole project in 2018.3?

Also, if I need to end up rebuilding my whole scene, can I just copy over all my asset folders from the 2019 version, or will there be issues?

 

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You can try to fix it. Downgrading isn't supported, earlier versions of the software don't know about later features. Why 2018.3 when there is the LTS version.
You can copy only your assets from one folder to another. But don't copy the meta files. So 2018 will import them again.

 

Thanks. I was told 2018.3 specifically by a client.

As for trying to fix the errors, when I try to launch the 2019 version in 2018, it couldnt launch normally. Told me to hit "continue" but things will be missing. My scene files are only showing the lighting and none of the assets or anything else. Not sure this is fixable.

Also, unrelated to this issue, but any idea when I copy my assets over from 2019 to 2018, they show without materials (they all look chrome) in the project window folders, but they look fine in the inspector? The only way to fix this is by selecting them all, then checking generate lightmaps off then on again. Almost like it wakes the project window preview images up, cause they all show up again after that.

 

You probably can "reimport" these. Your shaders aren't recompiled yet, probably. Possibly because of errors. There is a reason why Unity does not support downgrade.

 

Thanks, but it wasn't a downgrade. It was a new project I started, and just copied over the folders (minus the meta files). Seems like this was a bug...because once I selected and deselected an option on the mesh/material preview in the inspector, it fixed itself.

 

I'd try to talk your client into the latest 2018.4.x, which is basically the latest bug fix release for 2018.3. The new prefab and terrain systems were released in 2018.3.0 and there were a few bugs fixed since then (like with any x.0 software release).