Common Blender 2.5 Problems And How To Fix Them

With Blender 2.5 alpha 0 we’ve seen the first release in the 2.5 series, boasting a great many new features on top of the all-new event system – a major overhaul of one of the most central parts of Blender. As one can expect, many problems were readily found during the first few moments after the release. I’ve tried to summarize most of the problems that users may run into that are easy to fix or work around.

Incomplete/gray GUI

Some users reported that the GUI would look incomplete. This turned out to be a problem with paths that contained non-ASCII characters. Although it should be fixed in recent builds (as of this writing), if you still experience that, move Blender to a location that contains only ASCII characters in the path. So no accented or non-latin characters like ë, é, µ and so on.

Incomplete GUI
Incomplete GUI

If you want to see for yourself how broken this looks like, go into the .blender/ directory and rename scripts/ to something like xripts/ and run Blender. You’ll see something like the above image. Rename back to scripts/ to get your nice Blender 2.5 back.

Crash while starting Blender

In some situations Blender would not even start. This would happen where the user had PYTHONPATH in the environment variables, pointing to an older Python version, most often Python 2.6. This could’ve happened either manually, to get Blender 2.49(b) working, where in some cases it could get confused or not find the proper Python installation. Or another program might have added the PYTHONPATH variable and set it to some older, pre-Python 3.1 installation.

The net result of this would be an instant crash? The reason for it is pretty simple: Python 3.1 is incompatible with previous Python versions. If you start Blender 2.5 from a command-line and have that PYTHONPATH pointing to Python 2.6 (or even older, if you have it installed), then you’ll see from the error output in the console that it tries to load Python 2.6 modules, and fails miserably.

To easily work around this, and without touching your environment, create a new file called blender.bat next to the blender.exe and add:

Next time you want to start Blender 2.5, start blender.bat instead. It will ensure that Blender 2.5 will run properly. For now you’ll have to do it for each Blender 2.5 installation you do to a separate directory (if you install over your existing Blender 2.5 that already has the above created blender.bat you don’t have to bother, otherwise just copy the file to the new installation, too).

GUI going gray after a while

This is most likely a problem with your driver. Make sure you have the latest for your videocard. If that really doesn’t seem to help, and you have played with the OpenGL buffer drawing type in the Blender user preferences for the system (triple buffer or any of the others) to no avail, try turning of hardware acceleration. Often using Windows Classic theme will turn of those effects and Aero (on Vista and Windows 7 at least). If that helps the drivers are your problem – waiting for a better driver version is then your only option, unfortunately.

Other problems?

If you know of other problems and work-arounds, please don’t hesitate to tell so in the comments!

130 thoughts on “Common Blender 2.5 Problems And How To Fix Them

  1. Hi!, I have a question on blender 2.5 alpha 1, (windows 7 x64)

    I use a lot of textures on the materials, and when I import materials from previous 2.49 files, when I want to render, an error occurs, blender crashes, and when I open the file again, most of my textures on the materials are “canceled” or “dissapear”, even if it is a procedural texture, what could be the problem?

    this also happened when I tried to make a new material using new textures, imitating the imported materials.

  2. I had the incomplete UI problem too. However, after I change the root folder’s name from my language to English, the problem gone. So, I think using the folder’s name in English might help to solve this problem.

  3. How exactly do you find the blender.exe file. like can you walk me through the steps to get 2.5 working? I’ve got the same crashing problem. Would I find the blender.exe file in the 2.49 folder or the 2.5 folder? I’m not incredible with computers, a least programming and stuff (pretty damn good at blender). If you’d help me that’d be amazing!

  4. I have a similar problem to the post at the bottom of page 1. I get the instant crash and the console shows that 2.5 has found the 2.6 Python that my 2.49b uses instead of using the Python 3.1 that came bundled with the 2.5 build. I’m pretty good with Blender but a dunce with computers otherwise. In attempting to create a new .bat file I wrote.. set PYTHONPATH=blender on a wordpad .txt document or file, changed that to a .bat file, put that in the folder with all the other stuff for the Blender 2.5 build above (I guess that the same as next to)the blender .exe file. and then clicked it to open 2.5 as instructed in the directions for the “instant crash” work around. I can see a console flash up real quick and then go away, wat to fast to see what it says. Then nothing happens. Can anyone explain what I’m doing wrong or give a better step by step direction on how to get this work around accomplised. Thank you.

  5. Subtle. You just need a return after “PYTHONPATH=”, put “blender” on the second line, then save as .bat and run the file


    Hi my name is Dusan from Czech republic
    I love Makehuman nightly but I can not import any files .mhx to blender 2.5
    I’ve done all 3steps you described and nothing.
    I believe that there’s no problem with my computer(laptop)XP home Dell D830 with C++2008 and
    python 2.6 and 3.1
    I use both because in blender 2.49 I have no problem to import makehuman files
    But in Blender 2.5 I can not do it.I send text from console with hope that someone will help me:
    found bundled python: C:\BLENDE…….etc
    RNA_string_set:IMPORT_SCENE_OT_makehuman_mhx.filename not found.
    RNA_string………………………… not found.
    File “C:\BLENDE~1\.blender\scripts\io\”, line2128, in execute
    UnicodeDecodeError: 'utf8' codec can't decode byte in position 28:unexpected code byte

    Sorry probably this is something what is possible to manage but Iam not able…
    I've tried anything to do that myself but I need help….

    Send me detailed way how to set it or what to do to make import from makehuman nightly to blender 2.5 please….
    I do not know what I can do wrong….
    Also….I can not import to blender 2.5 anything
    .obj ….nothing works and both makehuman and blender are the latest releses…
    thank you

    • I read on makehuman blog that you already got answered. And your error (UnicodeDecodeError) points exactly into that direction. I thought we had fixed this part though :/ So thanks for your report anyway, need to check this out one more time then in the code of Blender :)

    • I assume you have an Intel video card? Unfortunately I have a hard time reproducing this problem. When time permits I’ll try to put up a debug build as well, so that people could help in finding the root cause for this problem. Until that is fixed, please try to not use actions where a new system window is created. User prefeneces can be switched to in any blender window through the editor type menu on the left side of an editor main menu. Same probably goes for rendering in a separate window.

  7. Same problem as PJ here- When I start “User Preferences” 2.5 crashes.

    Running the latest svn (June 01) happened on all versions so far trued. It’s a real pain.

  8. Hi!

    I´m having some trouble with render.when I try to setup my scene,add some lights, and changing the definitions of lights and shadows…and when I finally say blender to render, it just crashes!Anyone can help me with this?

    • Are you rendering to a new window? If so, this may be your problem. Please try rendering either full screen or to image editor. Hopefully this works better.

  9. Hello, I just downloaded blender 2.5 alpha 2 and the problem I’m having is that when I run blender it’s freaking slow, is soo laggy, I can’t work with it that way, I also have blender 2.4b and python 2.6 i know python 3.1 is included on the alpha version and it runs (as far as i could saw) well, but soo slow, my OS is windows 7 2gig ram, 1.7 processor, ati x1400 256M, the strange thing is that i also have ubuntu 9.04 (on dual boot) and it runs sooo quickly, it runs so well, I don’t understand what’s happening, on win I have all my drivers up to date, please help I would love to take a sneak peak on the alpha version on windows

    • Hi Oscar. I run Windows 7 too (ultimate, 64bit in my case). I have an ATi HD 4650, but I experience no slow down. You may want to try in user preferences > system settings in Blender to cqhange the Window Draw Method to see if any of the others give better performance.

      • hello jesterKing, thanks for your post, I just changed the window draw mode and the one that made it faster was triple buffer but it still laggy to work with it, so idk if there’s another thing I may change on blender to improve performance ‘cuz as you know I have also version 2.4b and it runs sooo well, very fast, so I think is not my computer at all, plz help

    • That indeed does look very weird. Have you also tried setting different drawing methods in Blender’s user preferences under section System?

      Also, please try to find where you can switch of or turn down the usage of hardware acceleration on the operating system side. Also make sure you don’t have any type of anti-aliasing enabled for the driver.

      I guess you don’t experience this with any type of OpenGL game?

      • ok.

        win7 home basic laptop it is.

        i tryed to go on to user preferences, blender tryes to load the window, then crashes, “stops working”.
        if there is another to set a drawing method, ill try it, but i couldnt find any files.

        when i change the desktop display to 16bit colours, the same thing happend, but it turns pink/white at the same time when morphing, lol.. looks like some acid trip.

        changing the resolution doesnt change anything.

        “Also, please try to find where you can switch of or turn down the usage of hardware”

        i cant locate this yet, microsoft messed up the control panel.. may not even be one, there is SIS settup program, but its weak, just used to adjust colours, brightness, gamma.

        ill try find a opengl game later, but being a laptop, i dont think many games will work, ill look for dev demos.

        hey, it could just be a misfit laptop, i hope, then you shouldnt have to worrie about it :|

        • Instead of using the User Preference entry from the top file menu change to them from the 3d view where you normally change editor type (bottom-left corner).

          For some cards+drivers creating a new window crashes (so most likely rendering to a new window will crash too – in that case render to image editor), and I have been unable to reproduce that (so hard to debug too :/ ).

          AFAIK you can force windows to not use hardware acceleration by not using an Aero-based theme (anyone who knows better, please correct me). Classic will most likely work for that.

          I think that I have currently no further ideas of what could fix your problem (except for SIS writing better drivers ;) )

          • awesome.

            got on to user preferences via editor type, changed the window draw method.

            they all work except tripple buffer, which was the automatic one.

            true what said about SIS drivers still :)

            Thanks jesterKing :D

            • Ah, great that it worked like this :)

              So remember to not render to a new window then, and no window duplications either :)

  10. I tried your .bat fix, but Blender 2.5x 64-bit still crashes on startup. I’ve been running 2.49b 64-bit for a while, and 2.5alpha2 32-bit, but the Alpha2 64-bit and this new 2.53 64-bit both crash on startup. I have 64-bit Python 3.1 and 2.7, and I’m running Win7 64-bit. I’ve updated all my drivers and it still doesn’t work. All Blender installs are in separate folders.

    Thanks for your help,

  11. I purchased and downloaded a DVD on how to create a human tutorial, and every since blender has crashed 34 times in about 3 days and it has never crashed prior to the times it has recently. It crashes when I try to recalculate and/or create quads/faces… it freezes and then just crashes and an error/ blender has occurred a problem pops up. It has never crashed before recently and I do not know what to do, bc its making it impossible to create my meshes when it crashes constantly! please help! Im on a 2010 Macbook pro, fully equipped. dont know what else to do… ive uninstalled and resinstalled blender 2 times since, still no relief… any advice????

  12. I can’t open any of the builds from the Blender official site without it immediately crashing. Interestingly, the builds that are independent on other sites (e.g. Ocean Sim) work fine. Maybe something/ someone corrupted the code by mistake??

  13. Blender (Not responding) when launched.

    2.73 was working. Crashed. When I try to restart it the window opens with the blender icon and name but a completely grey featureless window and then after a minute or so the window adds the words (not responding) later windows closes it or asks me if I want to close it.

    I tried launching 2.72b and it has the same frozen result.

    The odd thing is that if I double click a .blend file. It opens in 2.72b with very old user preferences.

    Nothing on the computer has been changed inbetween working properly and the above fault – just the crash of blender. (I then restarted windows in case that would help)

  14. Completely useless. The fix about crashing on start and python does not work at all. It will not load up at all and I need a program like this. I’m glad it is offered free because it would be completely useless and a total waste of money if I had to purchased it.

  15. I Was Moving The Timeline When It Dissapeared I Would Like Some Help On How To Get It Back Without Deleting The Whole Project. Please Help.

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