Blender 2.49 Users: Don’t Get Yosemite

If you develop 3-d models for X-Plane using Blender 2.49 on OS X, do not upgrade to OS X 10.10 (Yosemite).  Something changed in the OS that causes the python scripts to not load, which means you won’t be able to export.

(As a side note, I am of the opinion that if you use your computer for work, you should not install major OS upgrades without investigating first.  If Apple is going to break support for something intentionally, it will be in a major version.  Once you install the new OS, going back is hard.  So why jump in so fast?  These days I don’t believe that any one OS update is so much better than what was there before that it trumps keeping your productivity software working.  But then, as Chris points out, I am older than dirt.)

Update: Chris found a way to make Blender 2.49 work with Yosemite.  For reasons unclear to us, the Python 2.5 framework that comes with the OS in Yosemite is just a symlink to version 2.6 (rather than the real Python 2.5).  If you delete the symlink and put in place the old 2.5 binary from an older OS, Blender starts working again.  I’ll post instructions when we have something written up in readable form, but this is a tricky mod at best – you have to change admin-writeable files in your library.

Update #2: Hi guys, Chris here. Here’s an outline of the steps that you’ll need to take…and you’ll need to be an administrator of course since you’ll be running sudo. A basic disclaimer….you should have a full bootable and recent backup of your system anytime you mess with system files (even though this should be relatively straight forward). These instructions worked for us but you should follow them at your own risk.

1. Go into your time machine archives or find a friend that has 10.8 or whatever version of OSX you used to be on, and obtain a copy of the Python 2.5 version framework at this path and put it somewhere accessible:

   /System/Library/Frameworks/Python.framework/Versions/2.5

2. Open Terminal
3. Change directories by running

   cd /System/Library/Frameworks/Python.framework/Versions/

4. To be safe, type:

   ls -al

   to get a full directory listing. If you see 2.5 -> 2.6, you have a symlink from 2.5 to 2.6 which is what’s causing Blender to use the wrong Python version. IF YOU DON’T SEE THIS, YOU DON’T HAVE A PROBLEM!

5. Delete the symlink by running

   sudo rm -rf 2.5

6. Copy the old version of 2.5 into this location (pay attention to the dot at the end!):

   sudo cp -R some/path/to/the/good/2.5 .

7. Now as good practice, let’s put the permissions the way they should be:

   sudo chown -R root 2.5
   sudo chgrp -R wheel 2.5

8. As one of our artists discovered, if Step #7 fails for you because “wheel” is not a known group name, it might be a good idea to run Disk Utility and let it “Fix Permissions” on your drive.

About Ben Supnik

Ben is a software engineer who works on X-Plane; he spends most of his days drinking coffee and swearing at the computer -- sometimes at the same time.

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