# Builder crashing due to pa\_win\_wdmks.c assertion error

**URL:** <https://discourse.psychopy.org/t/builder-crashing-due-to-pa-win-wdmks-c-assertion-error/7912>\
**Category:** Builder\
**Created:** [May 25, 2019, 1:55am UTC](https://discourse.psychopy.org/t/builder-crashing-due-to-pa-win-wdmks-c-assertion-error/7912 "2019-05-25T01:55:51Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Andrew\_LK](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/andrew_lk/32/4875_2.png) [@Andrew\_LK](https://discourse.psychopy.org/u/Andrew_LK)\
**Post date:** [May 25, 2019, 1:55am UTC](https://discourse.psychopy.org/t/builder-crashing-due-to-pa-win-wdmks-c-assertion-error/7912/1 "2019-05-25T01:55:51Z")

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Win10  
PsychoPy 3.1.2  
Standard Standalone

\*\*What do I want to achieve: I was hoping to open the program…  
\*\*What did you try to make it work?: I tried uninstalling and installing a previous version to no avail.

Here is the error I get when I run “C:\Program Files (x86)\PsychoPy3\python.exe” -m psychopy.app.psychopyApp

A s s e r t i o n f a i l e d !

P r o g r a m : C : \ P r o g r a m F i l e s ( x 8 6 ) \ P s y c h o P y 3 \ p y t h o n . e x e  
F i l e : s r c / h o s t a p i / w d m k s / p a \_ w i n \_ w d m k s . c , L i n e 1 0 6 1

E x p r e s s i o n : F A L S E

The builder opens for a second but is unresponsive and crashes nearly instantly and without an error message, I have to dig to find the one above. I’ve looked around and it seems to be a very rare error involving portaudio but I don’t have enough technical knowledge to be able to solve this problem. Please help!!

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<div class="post-metadata">

**Author:** ![mirh](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/mirh/32/4625_2.png) [@mirh](https://discourse.psychopy.org/u/mirh)\
**Post date:** [May 25, 2019, 5:11pm UTC](https://discourse.psychopy.org/t/builder-crashing-due-to-pa-win-wdmks-c-assertion-error/7912/2 "2019-05-25T17:11:48Z")

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See

> <https://github.com/psychopy/psychopy/issues/2476>
>
> PsychoPy 3.1.2 (and 3.1.1, both 64 and 32-bit versions have been attempted) are …both crashing immediately after I launch PsychoPy and the builder window opens. I am getting the following error with 3.1.1:
> 
> Program: C:\\Program Files (x86)\\PsychoPy3\\python.exe
> File: src/hostapi/wdmks/pa\_win\_wdmks.c, Line 1061
> 
> Expression: FALSE
> 
> I’m not sure what the most useful system info is, but I am running Windows 10 home 64-bit (v.1809) on a Dell XPS 9550 from 2015. I believe this is an issue with portaudio but I can't seem to get around it by updating my sound driver or changing it to a default Windows one. 
> 
> Any help with getting PsychoPy to run on my machine would be supremely appreciated! Thanks!