Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Supported by

Version 3.3.5 is incompatible with macOS BigSur

Dear developers, particularly @Daniel and @sebastiaan ,

we are running experiments on participants laptops and had some problems to use OpenSesame on the brandnew MacBooks with macOS BigSur.

It was not possible to open our experiment. (Nothing happens, but OpenSesame loads forever)

It is possible to open OpenSesame, but not the experiment. Also it is not possible to do anything when OpenSesame is open. For instance, drag and drop of the items does not work.

I hope this is just a small bug and you can find a quick fix or workaround. Any advice is welcome.

Best regards,



  • I think Apple moved a few of the core python files required by OpenSesame.PsychoPy was having the same issues and it sounds like the fix was fairly simple. The thread is here:

    Hopefully its just as simple for OpenSesame as I really prefer it.

  • Hi, could you try out the python 3.9 beta version that can be found at

    I just want to know if this runs on Big Sur as the problem apparently was related to python 3.7 on which OpenSesame normally runs.

    If it works I will create a new package that also includes the osf and osweb extensions as I forgot these for the beta.

    Buy Me A Coffee

  • @Daniel

    I gave the beta a try with mixed results. From the start I could not change the backend of the default template (via dropdown menu) without the program freezing and requiring a force quit. I was able to open already completed experiments though.

    Trying simple emotion recognition experiments (imported images and key responses) everything went fine (these used xpyriment and psychopy back ends).

    Trying a Ponzo task using a mouse response and legacy backend failed. I had to take a screen shot (attached) to get the error codes as trying to select the text and copy caused the program to freeze completely.

  • Hi @Rrob,

    thanks for trying this. I think the last error you mention resides in an inline_script, in which there is a mistake in the code. Does this run on other versions of OpenSesame, that is, OpenSesame with a lower python version than 3.9? A possibility then is that Python 3.9 has become more strict with enforcing some coding rules.

    As for the rest, I have no clue what causes these issues. At least we are a step further than what @DahmSF reported, in that OpenSesame no longer seems to hang on load. It is weird though that you get a hang when changing the value of the backend dropdown. As far as I know, nothing extraordinary happens then (right @sebastiaan ?), as the backends themselves only get loaded once the experiment is started.

    I cannot really be of help here as I plan on delaying my upgrade to Big Sur for quite a while, as I read a lot of reports of suboptimal performance and other issues that I would like to see ironed out before I make the jump.

    Buy Me A Coffee

  • Hi Rob,

    does the explanation in your report mean that you were able to use the arrow up symbol to open the experiment from within opensesame? Or did you open it by a different trick? Also the run button should work then, right? (Because previously it froze by any click. Now it's not freezing any more on clicks in the main menu. Is that right? )

    Unfortunately, i do not have a MacBook to try it out myself. We just had the problems on the participants computers. I am wondering whether it is worth sending the link to participants.


  • @Daniel I tried the Ponzo task on an older machine with 3.3.5 and it doesn't work either. I haven't used this experiment in a long time so I'm not actually sure when it stopped working. The error does seem to change depending on the back end though, but its simply errors within the code not OpenSesame. I will try some longer studies I have as well as building something from scratch at on the beta at some point.

    @DahmSF I used the menu bar to open the file. It seems to work with the up arrow icon as well. Interestingly, the first time I tried to run the study it froze up, but after I force quit the application and ran it again it worked fine.

    Not sure why there are these strange freezing anomalies.

  • I can confirm the freezing issues on macOS Big Sur. They occur both when building myself or when using the Python 3.9 release. For me, they happen every time (it does not disappear when force quit restart).

    Is there any further debugging I can provide? Perhaps this macOS Big Sur psychopy issue is relevant?

  • Hi @IsaiahvH ,

    That's a pity to hear. To be able to fix this issue, I will need to be able to reproduce it, and I do not plan on upgrading to Big Sur in a long while; not until at least the 3rd or 4th patch release has been made, so until that time I can be of no help with this issue. Unless someone else steps in who can fix this, or at least unambiguously points out what the issue is so I can fix it in my version on Catalina, there is little I can do until after I have upgraded. Very sorry for this.

    Buy Me A Coffee

  • edited December 2020

    I did a quick Google search and found this:


    It seems to be an issue with Qt5 on Big Sur that afflicts all Qt-based applications. These links also propose a fix. Can you see if that works?

    You can set the required flag if you run OpenSesame from a terminal. Thus, if OpenSesame is installed in the applications folder, you first execute

    export QT_MAC_WANTS_LAYER=1

    once after opening a terminal and then launch OpenSesame with:



    open -a OpenSesame

    If this works, you can include the above flag in your ~/.bashrc or ~/.zshrc file (or config file of any shell that you use), so that it is set by default.

    Buy Me A Coffee

  • @Daniel Your terminal fix works on the most recent release and the 3.9 beta (I . I can use the app normally and switch backends without any freezing. It seems to mask the log screen after an experiment completes successfully or fails though (Only a white screen is shown). I would help more, but I don't have much programming experience.

    Always willing to test a beta on my machine (M1 MacBook Air with Big Sur) if you do end up working on this more.

  • edited January 2021

    Hi @Rrob

    The M1 has a whole new cpu architecture (ARM) and is not officially supported by OpenSesame. The app is built with the x86 architecture, so MacOS does a translation from x86 to ARM, which may cause unexpected issues like these.

    You could run Opensesame from source using conda. This has already converted most of its packages to ARM architecture, so if you run OpenSesame in conda, you should be running it natively. See more info here: Best is to use Python 3.8 or 3.9 as there have also been some problem reports about Python 3.7 on MacOS Big Sur.

    Buy Me A Coffee

  • @Daniel

    Thanks for coming back to this! It does appear to work using the conda build! I can't speak to any of the OSweb features, but local projects seem to be running ok.

Sign In or Register to comment.

agen judi bola , sportbook, casino, togel, number game, singapore, tangkas, basket, slot, poker, dominoqq, agen bola. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 50.000 ,- bonus cashback hingga 10% , diskon togel hingga 66% bisa bermain di android dan IOS kapanpun dan dimana pun. poker , bandarq , aduq, domino qq , dominobet. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 10.000 ,- bonus turnover 0.5% dan bonus referral 20%. Bonus - bonus yang dihadirkan bisa terbilang cukup tinggi dan memuaskan, anda hanya perlu memasang pada situs yang memberikan bursa pasaran terbaik yaitu Bola168. Situs penyedia segala jenis permainan poker online kini semakin banyak ditemukan di Internet, salah satunya TahunQQ merupakan situs Agen Judi Domino66 Dan BandarQ Terpercaya yang mampu memberikan banyak provit bagi bettornya. Permainan Yang Di Sediakan Dewi365 Juga sangat banyak Dan menarik dan Peluang untuk memenangkan Taruhan Judi online ini juga sangat mudah . Mainkan Segera Taruhan Sportbook anda bersama Agen Judi Bola Bersama Dewi365 Kemenangan Anda Berapa pun akan Terbayarkan. Tersedia 9 macam permainan seru yang bisa kamu mainkan hanya di dalam 1 ID saja. Permainan seru yang tersedia seperti Poker, Domino QQ Dan juga BandarQ Online. Semuanya tersedia lengkap hanya di ABGQQ. Situs ABGQQ sangat mudah dimenangkan, kamu juga akan mendapatkan mega bonus dan setiap pemain berhak mendapatkan cashback mingguan. ABGQQ juga telah diakui sebagai Bandar Domino Online yang menjamin sistem FAIR PLAY disetiap permainan yang bisa dimainkan dengan deposit minimal hanya Rp.25.000. DEWI365 adalah Bandar Judi Bola Terpercaya & resmi dan terpercaya di indonesia. Situs judi bola ini menyediakan fasilitas bagi anda untuk dapat bermain memainkan permainan judi bola. Didalam situs ini memiliki berbagai permainan taruhan bola terlengkap seperti Sbobet, yang membuat DEWI365 menjadi situs judi bola terbaik dan terpercaya di Indonesia. Tentunya sebagai situs yang bertugas sebagai Bandar Poker Online pastinya akan berusaha untuk menjaga semua informasi dan keamanan yang terdapat di POKERQQ13. Kotakqq adalah situs Judi Poker Online Terpercayayang menyediakan 9 jenis permainan sakong online, dominoqq, domino99, bandarq, bandar ceme, aduq, poker online, bandar poker, balak66, perang baccarat, dan capsa susun. Dengan minimal deposit withdraw 15.000 Anda sudah bisa memainkan semua permaina pkv games di situs kami. Jackpot besar,Win rate tinggi, Fair play, PKV Games