Can you easily export a .blend to a previous version of Blender? [duplicate]

Question

I have 2 versions of Blender, 2.79 and 2.9. I edited a .blend file that was made in 2.79 today in 2.9, then saved.

Now, I cannot open it in 2.79 anymore (it just crashes Blender). However, there are plugins in the 2.79 version that I haven't yet installed, or might not exist in 2.9. And I have to deliver some files.

I now that all Adobe apps allow you to export documents to a previous version if you need, but I couldn't find anything about Blender. I would prefer not to have to redo textures, etc.

Can I export the file from 2.9 to 2.79 easily?

Answer 1

TLDR: Is it possible? Yes. Is it easy? It's not one-click.

Each release of Blender may introduce new features that are not backward compatible with older versions. As a result, attempting to open a .blend file created in a higher version of Blender in a lower version can lead to compatibility issues. While Blender will make an effort to open .blend files from any version, the success rate is not very high. With the advent of collections instead of scenes, the scene will open empty. So going from 2.9 to 2.79 directly will not fly.

However, if you are willing to jump through some hoops, you can extract things of interest out of those files with the Link/Append functions under File Menu.

Just make sure to choose the right object. You will also need to make sure that modifiers and nodes that were added since were not used in the object you are trying to back-port.

I successfully yanked one of my characters out of a 2.9 version file and got it running on 2.79, but there was some fiddling I had to do and I wasn't doing anything too special rigging wise. Also remember that you must use Cycles in 2.79, Blender render materials are not compatible with Cycles/EEVEE.