Python ctypes access violation reading

I'm trying to communicate with a device through a DLL with python, but I'm getting "OSError: exception: access violation reading 0x00000000". I've read other topics, tried the solutions there, but nothing worked.

Here is the code:

from ctypes import *

Papo32 = WinDLL("lib\\Papo32.dll")
Interlnk = WinDLL("lib\\Interlnk.dll")
Intfac32 = WinDLL("lib\\Intfac32.dll")
Spider32 = WinDLL("lib\\Spider32.dll")

ACQ_setup = Spider32.S8_ACQSetup
ACQ_setup.argtypes = [c_long, POINTER(c_long)]
ACQ_setup.restype = c_long

chans = [1]
n_chans = len(chans)
chans = (c_long * 8)(*chans)

error = ACQ_setup(n_chans, chans)
print(error)

This is the error:
error = ACQ_setup(c_long(n_chans), chans_array(*chans))
OSError: exception: access violation reading 0x00000000

The error doesn't occur when the array is empty.

I have this from the documentation:

S8_ACQSetup

Syntax:
    result = S8_ACQSetup(Num, *Chans);

Parameters:
    Input:
        • Num - long
          Number of measured values per channels
        • Chans - long
          List of measured channels

    Output:
        Result of the function (long):
        If the result of the function is non-zero, an error has occurred.

Description:
    The desired channels will be activated for measuring.

And I'm following this example in VB5, provided by the manufacturer:

Declare Function S8_ACQSetup& Lib "SPIDER32.DLL" (ByVal num As Long, Chans As Long)

Dim ChanArray(10) As Long

ChanArray(1) = 0
S8_Error = S8_ACQSetup(1, ChanArray(1))

Thanks in advance