OSError: exception: access violation reading 0x0000000000000000
19:59 12 Jul 2026

I am trying to install a python driver, snAPI, by which I will be able to control a piece of lab equipment, a time tagger. There is no apparent error when I pip install the driver, but when I run a demo program on it, I get the following error:

runfile("C:/Users/edmcubed/anaconda3/Demo_TimeTrace.py',` wdir='C:/Users/edmcubed/anaconda3")
Switched to: TkAgg
Traceback (most recent call last):

File ~\anaconda3\envs\py310\lib\site-packages\spyder_kernels\py3compat.py:356 in compat_exec
  exec(code, globals, locals)

File c:\users\edmcubed\anaconda3\demo_timetrace.py:33
  sn = snAPI()

File ~\anaconda3\envs\py310\lib\site-packages\snAPI\Main.py:235 in _init_
  self.initAPI(systemIni)

File ~\anaconda3\envs\py310\lib\site-packages\snAPI\Main.py:403 in initAPI
  ok = self.dll.initAPI(SBuf)

OSError: exception: access violation reading 0x0000000000000000'
    

For context, the above happened when I ran the demo on Python 3.10 and Python 3.13. I was able to get the program to work successfully when I ran in on a different computer with Python 3.12. However, I am unable to fully understand the error message. Has the 'dll' been downloaded to the wrong place or is there a conflict with the Python version?

Regards, Luiz

       
           
         
dll driver access-violation oserror