Error report version 2023.2.3

If this template helps then use it. If not then just delete and start from scratch.

OS (e.g. Win10):
PsychoPy version 2023.2.3
Standard Standalone? (y/n) Y
What are you trying to achieve?:

Ok I have installed this version on a different PC now this one posts the screen rate message and then hangs with the following error message posted

wx._core.wxAssertionError: C++ assertion “GetEventHandler() == this” failed at …..\src\common\wincmn.cpp(470) in wxWindowBase::~wxWindowBase(): any pushed event handlers must have been removed

The above exception was the direct cause of the following exception:

SystemError: <class ‘wx._core.WindowDestroyEvent’> returned a result with an error set

Please help because I now cant use Psychopy for anything on these machines

What did you try to make it work?:

What specifically went wrong when you tried that?:
Include pasted full error message if possible. “That didn’t work” is not enough information.

Ok I managed to sort this by changing the monitor from a rasta to a led monitor - can anyone advise?


For some reason this error has recurred and I now cant run Psychopy on my PC.
Can anyone help please?

Ok I am beginning to make some progress on this - currently two of my PC versions of v2023.2.3 refuse to run.

In the current case

I tracked the error down to this code in the lastrun version of my script

if 'frameRate' in expInfo and expInfo['frameRate'] is not None:
    frameDur = 1.0 / round(expInfo['frameRate'])

For some unknown reason it recovers a frame rate of 0.23 (how this comes about is beyond me) and I guess rounding this value gives 0.

A bug I guess?

Anyway if someone could help I would be very grateful. I have expended a lot of effort getting my code to run and now it won’t - through no fault of my own.

In desperation


Searching on the forum I can see that it might be related to your monitor specifications. Try choosing a different monitor in Monitor Centre.

In the words of @TParsons

“wx is the Python package which the PsychoPy app uses to create its interface - so this most likely won’t be affecting your experiment or saved files. It looks like it’s looking for an event (e.g. a click on a button, pressing a key, etc.) and something on the back end isn’t liking it. What were you trying to do when this message appeared?”

If it happens at the end of the frame rate check then perhaps there’s some code in Begin Experiment causing the issue. Do you get the error with a simple experiment with zero code?