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!

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

  1. I have a problem with the middle mouse button preference.
    Doesn’t matter which option i choose It always rotates the view instead of panning :{

    Please tell me if you’ve found a solution for this.
    Thank you.

    • In the later revisions after Alpha 0 you can actually change that in the user preferences in the keymap. For newer builds, see the right sidebar. The two build links will point to my latest builds, which I create with the same settings as releases (and alpha 0. And the exception of the added WITH_BF_RAYOPTIMIZATION=True ;) ).

      Please try those later versions and see how changing keymaps work for you.

      • Middle mouse need to have the pan option working.

        Jester you build left it out entirely I hope this isn’t how 2.5 is gonna be.

        • You can set this yourself in the user preferences:

          ctrl-alt-u > input > map: View 3d (change from Window). Remap view3d.rotate and view3d.move

    • What you probably have is a keymap collision. The keymap editor doesnt handle collisions yes so if another tool is using your new keymap and has a higher hardcoded priority then you will not see any change

  2. Is there an easy way to move your keymap from one install to another of 2.5? I install the latest of your builds, then have to map my keys again. Is there a file I can just copy?

    • You can save your keymap to a file in the keymap editor. This is a python file, which you can load and run in blender when you want to import those settings.

  3. I happen to have troubles with my python version too, but in linux. Do you know some workarounds on the subject?


    • If you have PYTHONPATH set on your system, you should be able to override that in a terminal from which you start Blender.

      Otherwise, care to elaborate a bit more on your Python problems? What kind of error output? Symptoms?

  4. I cant seem to find the subsurf modifier in the modifier tab. does anyone knows where it is located in the 2.50 alpha 0 build?

    • The Subsurf modifier has changed its name to Subdivision Surface. It is still located in the modifiers tab, 2nd from the bottom in the ‘Generate’ column.

  5. 2.5 is impress , I like new interface…but….BUG no.1 – Import …3DS…not working…for interier designers it is catastrophic…Internal renderer is great to, but when you use a Area light with Raytrace shadows, Smooth is not working…like Flat setting…

  6. Blender 2.5 is absolutely fantastic, but just one tiny thing makes it absolutely unusable for me.
    The problem is that I have to click-drag RMB to grab vertex and CLICK YET AGAIN LMB to release it! What’s with the second click?!?! I believe ‘Drag Immediately’ checkbox supposed to deal with this but it does nothing….
    Or am I missing something?

      • Now you have got to be kidding!..
        Just to check if that wasn’t a dream I’ve downloaded and installed v2.49. Yes — the DEFAULT behavior is like I’ve described (click to grab and click to release). But when you check ‘Drag Immediately’ button (Preferences|Edit Methods|Transform:Drag Immediately), the behavior changes to what it suppose to be (and IS in every other modeling package). Turns out 2.49 is actually a MORE EFFICIENT modeler?!
        I wonder then what exactly ‘Drag Immediately’ button does in 2.5 ?!?!

  7. On Windows 7 problem on Aero theme the drivers are not the problem but the blender itself. The Blender 2.5 Alpha 0 should be using the latest Visual C++/.NET Redistributable to supports Aero Theme at Windows 7/Vista.

    I hope this helps at the next official builds.

  8. My problem is that when trying to zoom in and out of the UI, it will suddenly go MASSIVE, and will be a real pain to get back to a useable size again. Unfortunately, I cannot use 2.5 until this is fixed.
    BTW, does anyone know how to Copy – Location, as used to be on CTRL+C menu?

    • Hmm, most of visual problems are related to drivers, although siraniks suggests that also redistributables need to be checked (which I personally find hard to believe, but it better be checked). So at least try to ensure you have the latest drivers for your videocard.

      I’m not sure where Copy>Location has gone, but at least you can do ctrl+c/ctrl+v when mousing over data inputs.

  9. Hi Jesterking,
    I was wondering where did some useful py scripts go, like:
    -Solid wireframe
    -Solidify selecction


    • Not all scripts have been ported yet. I’m sure that nearing the end of the Blender 2.5 development timeline, somewhere spring 2010, an effort will be done to port over the most useful scripts.

  10. Whenever I open up Blender 2.5, it has a complete mental breakdown. The entire interface screws itself up for no reason at all. Can someone please explain to me what’s going on?

    I have Windows Vista Home edition and the latest Python installed….?

    • If the screw-over looks anything like the screencapture, then check its instructions how to fix.

      From Blender 2.5 on you won’t need any extra Python installed, btw. Python 3.1 is fully bundled with the Windows versions of Blender, and it is preferrable to not have any other version pointed at by PYTHONPATH.

      Otherwise, check drivers and such, to see if they are most up-to-date.

  11. Hello,

    i can’t find the Bevel option in the ‘w’-Menu – the bevel modifier works, but if I just want to bevel only one edge it will just work with the bevel-option…in the ‘w’-Menu

    I need help in this point…


  12. The edge/face select mode stopped working for me (maybe is a problem of my ati hd3200) in blender 2.5, i noticed that disabling the VBO option from user preferences can solve the problem.

    • Hmm, that would point in the direction of the ATi driver indeed. I have ATi HD 3150 and ATi HD 3450 machines myself, and I have not yet experienced the mentioned problem. I do run the latest drivers to my knowledge.

  13. Love 2.5. It is awesome.I run a few PC’s and i have some mouse problems..All my mice are logitec wireless and for some reason The MMB does nothing on one mouse and works fine on the others. Not a biggie but it is kinda weird.

    P.S and that mouse MMB works fine with all the other programs I use.

  14. When rendering out audio with FFMPEG the movie file becomes dark. Rendering out with any other format works just fine. Just the gamma looks like it decreased significantly when rendering with FFMPEG. Alo, I know in previous version, you can make a loop cut by pressing CTRL+R and then press any number button to get that many cuts. In 2.5, it seems like you can’t do this anymore.

    • Start a loop-cut, then check the operator properties in the toolbar (default T-key, then left bottom). Right after the cut, change the amount of cuts before doing anything else. You can change until you’re satisfied with the number.

      This is also how many tools work in Blender 2.5. Take for instance subdivide – you can change the level of subdivision in the operator properties panel while you have the tool active.

    • Yes I was trying this out on my new iMac, 10.5 snow leopard, setting up the fluid simulation seems fine, but clicking bake just holds the program without showing any fluid results. have to hit escape to continue with no result. Shame!

      • update
        the bake IS working, it just doesn’t show it until it is complete OR you escape and play the animation back. display error I guess.

        • OK update update,
          no way to export the fluid mesh as an animation, (unless you want to manually go frame by frame… this IS A SHAME as that is what I use blender for, it’s fluids. 2.4 CAN export multi frame mesh objects 2.5 doesn’t seem to work the same.

  15. I’m using blender 2.5 in a Macbook pro. I was previouslu using 2.49.
    The new version does not allow me to render in any way, The preview window show a grid and nothing comes out either in the window or in any file out.

    Any clue ?

  16. My tabs go into randomnized purple flicker as I start it up…I started a topic in the…umm…I think it was Blender test builds section on the forum called ‘purplish issues’…
    Already tried restarting and downloading it again…
    added the URL to the pic probably above…

    • That looks very wrong indeed O.o I assume you have tried updating videocard drivers and if that didn’t help, you tried turning off hardware acceleration features for your card? Easiest would be to use the Windows Classic theme.

  17. Hey I tried the blender.bat solution but Blender still keeps crashing anyway so I don’t think that that is my problem.

    This same thing has happened on two different computers, Blender runs for about a week and then won’t load anymore… On my home computer (XP pro – 32bit) it crashed during a render and then wouldn’t open anymore, And at my office (XP pro – 64bit) it just wouldn’t open (I was not doing anything at the time).

    But I look forward to using it as soon as all the problems are gone and it is set loose as 2.6 ;)


  18. Hi

    It’s great to do this … some of the problems that commonly I have are:

    When I open a file created in version 2.49 and going to the menu of the modifiers and press the middle button of the mouse to move it up all gets too big and distorted, look:

    The other thing that happens to me, is that when I put the subsurf and I selected a vertex … the 3D manipulator is at another point far side of the selected vertex, look:

    And the last thing that happens to me, is that after working in Blender for a while, I can not close this, just does not close normally when I press the X in the corner … and I have to close from the monitor task.

    I do not know if this happens only to me, but it is an Alpha version jejeje, so it’s all very well, the developers are the best;)

    Someone had trouble opening a file made in version 2.5 to version 2.49?


    PS: The files. Blend can be downloaded from this project (to test or modify)

    (in Spanish)

    • You should be able to get the view back to normal using HOME.

      On subdivision surface modifier: that seems to be a bug indeed. Looks like the cursor is not updated to the optimal drawn mesh cage.

    • I also have the problem where I can’t close Blender normally after using it for a long time. I suspect there is some kind of memory leak or pointer problem. I haven’t found a reliable way to reproduce the problem quickly, yet.

  19. I’ve noticed that using nodes can cause crashes, but at odd times. Adding a texture to a rgb curve node crashes Blender, but only when you connect the curve node to anything else.

    • The node editor has not yet had the amount of love as for instance the animation tools :( But I’m sure that whenever Durian progresses towards final stages, that this will get more love too.

  20. How about, guess most common on Ubuntu 9.10 (Linux) segfaults, did this every time after a first successful run, seems to fix itself by passing just a space and some chosen letter after; terminal “./blender” ex: “./blender a” can someone care to elaborate on WHY this helps? After I’ve done this I can run Blender normally.

  21. Dave: In Blender 2.49, when you use control+scrollwheel and the buttons are small or large (depending on which way you turn it) you can move the buttons, dragging the mouse normally with the scrollwheel pressed.

    And when I move a bit up is when it distorts everything T_T


  22. Here’s how I do the Python thing. I have the following environment variables:


    They are set to point to the appropriate directories. I also have a blender.bat file which has in it:

    set PythonHome=%PythonHomeXX%
    set PythonPath=%PythonPathXX%

    with XX being the appropriate python version for whichever version of Blender I am running. It works great.

    • Nice :) Be noted though that Blender 2.5 on Windows comes with Python 3.1 bundled. You can find it in .blender/scripts/python/lib, and this is where Blender 2.5 will look for if no other location is given.

    • I still have problem with that.
      I made a bleder.bat in which is
      set PYTHONPATH=F:\Program Files\Blender 2.50\win32-mingw_b25897\.blender\python\lib

      But if I try to start them it will crash down. The same if i try to start blender.exe.

      • Can you try still with

        set PYTHONPATH=

        instead? I assume from your PYTHONPATH that you build your own Blender. Can you also try with one of my recent builds to see if they crash too? Currently I don’t have a proper MingW environment set up to verify it for the same settings as I use when building with msvc.

  23. i have a problem in blender 2.5 in loading large or complex scenes/models. simple stuff blender can load, but not the main ones im working on (python scripts had been taken out of it, but bone structures and subsurfs and similar left).

  24. I’m having a problem with copying objects in blender 2.49b. When I copy an object more than one time and move the copies and save the file, the objects are on top of each other when I load the file again.Sometimes I find the objects in other places different from the original place. I tested it on Ubuntu Linux 9.10 32-bit and the Machine is AMD Phenom II X3 720 BE with 4GB RAM and nVidia 9500 GT.Any Help would be appreciated. Thanks.

  25. HI a couple of things… How do you put a background image in the 3D view??? I can’t find anything.
    Also get some strange things happening when I cntrl scroll button resizing the button window.. it goes completely wacky, half of it disappears and it stretching like 3 miles sideways

    • You can add a background by clicking on the little + sign in the upper right-hand corner of the 3D display, which will expand the view properties. Towards the bottom, you’ll see the Background Image tab.

  26. Im using Ubuntu 9.10 here, blender 2.49 working just fine… but 2.5 is veeeeery slow, unusable. Maybe thats ’cause I’ve got a ati x1650 card,…. but since 2.49 is fine, maybe something could be done….

  27. For ubuntu 9.10 I ended up having to install Python 3.1 from source, seems blender needed python compiled with –enable-unicode=ucs2. The version on ubuntu had ucs4 enabled.

    I also had to remove all the desktop effects (compiz) with desktop effects enabled blender 2.5 was very unstable. Menus would stop responding and I could not exit blender with out having to kill the process.

  28. I like the new version :) Won’t be moving over from 2.49 for a while, but it is definitely impressive.

    Just a quick question, where have the gestures gone? They were one of my favourite and most used features! I cannot tell you how disappointed I was when I opened 2.5 and left-dragging the mouse did nothing.

    Is there any fix for this?


  29. Hi,

    does anybody know how to get the Spacenavigator working again? It worked just fine on blender 2.49b. I’m using Windows 7 64bit.

    Thank you in advance,

  30. Hy,

    maybe you are able to implement a new function … to round edges…so that we dont need to bevel 4 or 5 times if we need rounded edges…?

    mfg Triac

  31. Hi,

    I try to put a background image. I’ve found the tab, but I try to enter a path and it do not work. I’ve expected the same open button than the one in the texture menu.

    What I’ve missed?

    More, is there any documentation for the new 2.5 version?

    Thanks for your help,


    • I confirm, using linux mint here, and the background-image field brings up little empty gray window and not a file browser.
      Writing a file location doesn’t seem to work.
      I’m off to check the blender bug tracker thingy, it’s probably already there.

    • Okay… my mistake, it’s not a bug, just not super intuitive. You have to first open the image with the UV/Image editor, then it shows up in the little gray window.
      My bad.

  32. Triple-buffering (the default window draw method) is extremely slow on linux with a recent ATI card and the open source 3d drivers – slower even than software rendering. This can be fixed by changing preferences -> system -> window draw method to “overlap”.

  33. 2.5 looks fine, but I don’t think the new interface is complete, becouse for example, in the world menu there is no button for adjusting the exposure level. Is it out for ever? Was it moved in another menu? How could I find it?

    • I asked around, and my impression is that exposure will be gone from these settings. Instead, the way to work with gamma is through the composite nodes.

      • Thank you for answering to my questions jesterKing. I still think that the exposure adjusment must be a part of the world settings, it’s simple and nice, it’s PROFESSIONAL: why 3dsMax would have three exposure manners in the environment panel (linear, automatic and logaritmic), and Blender- NONE?!

        • That’s a good question :) But I’m sure that these issues will be investigated more closely when they get relevant at least for project Durian. Currently the main focus of the work is on animation tools, sculpt tools and such (and getting the UI in better shape still, enough open issues there :O ). If this is really important to you, I suggest you write up a good proposal with proper arguments for instance on the wiki, and then show it to the developers in #blendercoders or on the funcboard mailing list).

          • I’ll think about your sugestion seriously. Anyway I’ve tried some renderings using composite nodes and I like the results.

    • Hmm, at the very extremes of zoom out it seems to go all bonkers indeed. Fortunately you can use the HOME key to get a sane looking layout again. I’ll notify the developers of the problem (it happens in other properties sections too when horizontally layed out).

    • Indeed, the choice of optimisation always depends on the type of your scene. Maybe we can get André to write up some more detailed description on the inner workings of his optimisations, in such a way that artists understand about them too.

  34. hi..i have a weird problem. (ctrl-alt-u > input > map: View 3d) i don’t have any other beside window. Is there something missing?

    • Nothing missing. It’s not very obvious, but you just need to click into the text entry widget that says Window, then remove that text – you’ll be presented with a dropdown that’ll show you all available keymaps.

  35. I have observed some changes concerning the mesh tools. Maybe I’m wrong but there is no bevel edges command in the mesh tools menu, and the extrusion means only extrude region, there is no option for extruding individual faces, I don’t understand why. And a positive remark, I’m glad that the brigdge command exists, it is very helpful (for me).

  36. I just downloaded 2.5 start new and go to scroll and my veiw begins to go dark the more I scroll the darker the scene become, but when i click on the scene it comes back just one click. Thx Frank

  37. I just installed blender 2.5 Alpha 0 on my mac and I can’t open my old blender files. When I run it the files shows up on the listed blender files that I have, but when you press it blender says “error, cannot read file.” I tried opening the files in blender 2.49b and it worked fine. Any way to fix this?

    • i think that is because of python. –
      your old blendfiles are made with some funktions(modifier or so) in blender that are based on a previous version of python.
      2.5 cant read it cause of python 3.x instead of 2.x

      or it is something completely different XD

  38. anything new about the “background Image” thing??
    i tried typing in the path of my image, but its useless.
    also you can’t open a filebrowser..

  39. This is the first time using blender and i having a horrible time using it because the screen is just black for it.

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