Tips for bug reports

Today: some friendly advice for filing a good Blender bug report!

  • Submit the bug to the Blender bug tracker. I know it’s not the greatest bug tracker in the world (and has a bad habit of showing blank screens and errors), but it’s still better than posting on where it might never be seen by a developer (or having been seen, might be forgotten.)
  • Attach a file! It says this in big letters when you click the submit button, but people ignore it all the time. If the bug exists even on the default scene, check that it’s really the default by clicking Load Factory Settings in the File menu.
  • Make that file as minimal and easy to test as possible. Delete unnecessary objects, scenes, and screen areas. For example, if your bug report says to reproduce by adding a wave modifier to an object, save the file with that object selected and the modifier properties panel showing.
  • Give the file a good specific name. Examples of bad names: “test.blend”, “error.blend”, “flower.blend”. Better to give a short description of the error, and maybe even prefix it with your username to make it unique: “nicholasbishop-sculpt-grab-explosion.blend”.
  • Give steps to reproduce the bug in that file. If possible, also give steps to reproduce from the default scene. If you are unable to reproduce it from the default scene, say why.
  • Always say which version you tested with. Be specific (e.g. “2.63a” rather than “latest release”). If you’re testing something newer than the latest release, indicate the SVN revision. Say where the build came from; (give link!), official release, build bot, compiled yourself, etc.
  • Test something recent. It’s fine if you are staying with 2.62 for production work, but if you find a bug check that it’s in 2.63a too.
  • Give your operating system (plus 32-bit/64-bit) and other relevant system info like graphics card and drivers. If you’re not sure what’s relevant, it never hurts to attach the system info file that Blender can generate from the Help menu.
  • One bug per report! If you find more than one bug, even if it’s related to the same tool, file multiple bug reports.
  • No feature requests in the bug tracker. Often these sneak in as part of a real bug report, but these requests should go to or an email to the module owner.
  • Write as clearly as possible. I know many users are not native English speakers, but it helps to use punctuation and keep your descriptions as concise as possible. For those that are native English speakers, no excuses for not paying attention to the red squiggly beneath misspelled words! ;)

It may sound annoying to follow all these steps, but remember that if you don’t, the developers waste time figuring it all out themselves or trying to coax the information out of the user for each bug. Some developers like Sergey, Campbell, and Brecht handle a huge number of bug reports; you can really help them out by filing good ones.

22 thoughts on “Tips for bug reports”

  1. Don’t forget to check if the bug doesn’t exist yet!
    I have to say, sometimes I don’t declare some bugs, because the search engine of the bug tracker is so uneasy, so weird… Ii is really a pain to check if bugs already exists or not. Something should really be done on that

    1. That’s actually why I didn’t mention checking for an existing report. Searching should be one of the most easily accessible features, but our tracker makes it way too difficult. So that’s on us to fix; if there is a duplicate report then one of the devs will mark it as such (hopefully in a courteous manner :)

  2. Good points.
    Btw are you aware that the procedure you described very often can take you half a day to be done (especially dissecting a blend scene to find the cause)? I mean, not always the why and the where the bug is happening in a scene is obvious… :)

    1. It’s true that it can take a while, but think of it as distributed problem solving. If users submit bug reports without taking the time to do this, then it’s up to a relatively small handful of developers to do it for them. On the other hand, if each user does spend time creating a minimal .blend file, that cost is amortized over many users rather than the quite small number of developers.

      Anyway, these are just suggestions :)

      1. Oooops, I wasn’t expecting a real answer. :)
        Of course you are right, Nicolas, I was only pointing to the fact that sometime is really difficult to find the bug source in the scene and that in those cases you are going to spend a lot of time to dissect the blend (probably the reason not a lot of people submit to the tracker the bugs they find).
        For example, a couple of years ago I was collaborating with a studio for a job made entirely in Blender, that then was a very buggy pre-alpha, I think; it was almost impossible to submit all the bugs we found (2 or 3 a day), we should have stopped the job to prepare the blends for the submission to the tracker. :)

  3. Hi guys. Please help. I just can´t use this Blender in a XP system. After installation and try to open the program, a screen opens and suddenly close and nothing happens. This Xp is with latest versions and service packs uptodate. I´ve downloaded the setup twice and both have same prblem. Nothing at applicattion log in Event viewer. Any hint?

    1. This is not the best place to ask. See the original post you are commenting on for where bug reports should be posted.

      The fact that you are still on XP is a big red warning flag. Microsoft officially ended support for XP back in April (over a decade after XP’s initial release). It’s way past time to upgrade or pick a different operating system. If money is a concern then of course there are many zero-cost Linux distributions.

  4. Thanks for the answer, Nicholas. I agree with you that XP is not a reliable OS since Microsoft does not support it anymore but, if there´s an install program for this system available for download I think that is tested and can be used. If you say that is not secure to run in a XP system then you have to remove it from download options. I do not intend to run any Linux system by this moment. It could be a good idea but I don´t have time to do this by now. Thank you very much.

  5. Blender”STOP WORKING” MESSAGE AGAIN.. like 2.71. ! in w7 64 bits!

    Problem signature:
    Problem Event Name: APPCRASH
    Application Name: blender-app.exe
    Application Version:
    Application Timestamp: 542eba9b
    Fault Module Name: MSVCR120.dll
    Fault Module Version: 12.0.21005.1
    Fault Module Timestamp: 524f83ff
    Exception Code: c000001d
    Exception Offset: 0000000000092bc3
    OS Version: 6.1.7600.
    Locale ID: 1033
    Additional Information 1: 9c5b
    Additional Information 2: 9c5b99d1538af1465d6588ee6e30c6d2
    Additional Information 3: ffa6
    Additional Information 4: ffa6c829f7fac5222bb75dc93477b4fc

      1. Hello, Nicholas!
        A question – is it possible to make dynamic topology addon, that will adaptively subdivide selected polygons in edit mode in dyntopo manner, keeping the amount of vertices of a selection border untouched?

        1. Hi! I haven’t been involved with Blender development for a few years now, so I can’t speak to whether something like this is possible. I’m guessing people on might be able to suggest something. Good luck!

          1. May I ask a theortical question – is it possible to hire you for a such kind of a task?
            You are familiar with dyntopo engine and math behind it, so if you have outperformed the dynamic version, you can probably solve the static one.

          2. And thank you for dyntopo as well, by the way.
            Was following its fevelopment since unlimited topology by Farstary.
            Damn, you nailed it so nicely^^

  6. I m learning blender for hobby in 2.70 v and i see 2 months ago that 2.74 v and 2.76 v just dont open. it opens a grey window and instantly closed so i think i must continue with 2.70 that works perfectly until corrected the problem that exists in new versions… btw blender 2.70 is realy fantastic program…!!

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