Hi!
Blender 3.3. I load a file saved in version 3.6 and get “File written by newer Blender binary (305.9), expect loss of data!”
The Blender 4.0 Release Notes says that
The Blender 4.0 Release Notes says that
The mesh format changes from previous versions are now included in the Blender file format.
Blender 3.6 LTS can read files from 4.0, but earlier versions cannot.
**Blender 3.6 LTS will save meshes in a format compatible with older versions of Blender, so it can be used as conversion tool if needed.**
See the section in the Python API section for more details.
I think you would need to have some Python knowledges in order to get what it says.
However, what you can do is:
Open your Blender 3.3,
Go to File → Append,
It will open pop-up window, find in there your .blend file and double-click on it to open it,
There you’ll see a lot of folders, you need to open the Object one,
Now just select all the objects from that folder and hit the blue button in the right corner called “Append”.
Now you may see that all of your objects have been added to your current scene. Now just save your file. Next time you open it, it should work without any errors.
Or, just open that file in Blender 4.0, save it from there and then try to load it from 3.3
Why should this be a bug?
The default behaviour for blender is that compatibility works just in one direction. Newer versions can open files that were saved in older ones.
There’s some hierarchical structure in their fileformat, so you could try to open things in older versions, but if a special entitiy in that file didnt exist in the older blender verison it at least wont work there.
These notes in the 4.0 release tell that the mesh format itself in the blender file has changed. (And thats problematic as meshes are a very central thing for blender.) So it wont be possible loading 4.0+ files in 3.5 and prior.
3.6 is the bridging version, as it can read 4.0+ but write to 3.5 and prior mesh format.
The problem is in organizing the work of a dozen modelers and animators. Some don’t want to upgrade to newer versions of Blender for some reason, others want to upgrade. I need to understand whether it is possible to organize work in different versions on different pipelines or everyone will have to switch to a new version. Prior to version 3.6, there were no file compatibility issues. And this turned out to be a surprise, since there is no information in the 3.6 LTS Release Notes.
First of all careful, I didnt mention it in my last post but the post you marked as solution wont work that way. If a version 3.3 doesnt have the filereader to load 4.0 meshes appending wont work either. Saving it in 4.0 and opening in 3.3 also wont work.
And the hard truth is that if you work in an environment where different blender versions are used in parallel it can/will lead to problems and data loss.
There is NO guaranteed compatibility for newer file version in older binaries. Many things will load, but not ALL and the parts in question might be gone on saving.
You can strictly force separation and just load 3.5 files in blender 3.5 and 4.0 in blender4.0 or you should have the same version for the team.
Thats not true, it just didnt cancel out, but instead load it as good as it could. But eg have a look at some GN nodetrees when opening them in older versions.
Its blenders native fileformat. You could say it reflects the current state of blenders featureset and there is no way back. You would have to decouple the filereader from the main app version to make them futureproof.