[Help] Can't load scene created in Unity 5.2 in Unity 4.6 or 5.0

Unity Engine
1

i made the mistake of authoring the Editor Plugin I am writing in Unity 5.2. Now I’ve come to release it and I am trying to load the project into earlier Unity versions. I have tried to load it into Unity 5.0 and Unity 4.6.

Whether I simply copy the working 5.2 project directory to a new folder and open it with the earlier version or export it as an asset and import it I get the same issue, which is as follows.

The project loads, sometimes with some weird references to guids and metadata (if copying files) but otherwise my extension appears to be working fine. However, when I double click my sample scene to load it I get a completely empty scene loaded but I don’t get any errors, just a blank scene.

All the scene contained was a canvas with an image and a few new UI controls. Is there any way to get this to load?

Thanks

2

This is a bit convoluted, but it might shed some light on things.

Make a 4.6 project, save off a scene containing examples of each of the things you think you use in your test scene. Set the Editor to export as FORCE TEXT and save that .unity file.

Now go into Unity 5.2 in a new project, remake the same scene, export as FORCE TEXT, and save that .unity file somewhere else.

Use a text editor (or diff) to see the differences between those two. Ignore the guids, see if there are structural issues that you could hand-repair in your real 5.2 scene to get it to load in 4.6.

Obviously, you would have to get your original 5.2 scene to save as FORCE TEXT as well. I wish Unity would make that the default asset save mode and just eliminate binaries entirely!

Also, ask yourself if it might be faster to just rebuild that test scene too.

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3

I was really hoping to avoid recreating it, and the scenes are usually meaningless to me.

If there is an issue, why isn’t it reporting an error opening it?

Thanks for the reply.

4

I’m afraid that Unity projects have never officially been ‘downgradable’ in the way you’re trying to do - sometimes people get lucky and things work because the data formats didn’t change too much between versions, but other times there is breakage, as you are seeing. From 4.6/5.0’s point of view, your scene file is essentially corrupted.

We should do a better job of reporting errors when opening a scene like that, but we’re not going to go back to 4.6/5.0 just to add that kind of reporting in now.

5

Thanks.
here is what worked for me

  • opened the project in 5.2
  • changed serialization to force text & visible meta files
  • then opened the project in 5.0
  • and it worked
  • backup your project before any changes

Thanks again

6

ALSO, this is a great time for everybody to please start using source control… do it today with git… it’s EASY!

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