OSError: [Errno 22] Invalid argument when using readlines()

Question

I am having trouble loading some data into python using the readlines() method. The strange thing is it seems to work perfectly fine in another directory, with the same size of file and same file name. The size of the file is quite large (about 2.6 GB) which is probably causing some problems. I've looked at the post: "OSError: [Errno 22] Invalid argument" when read()ing a huge file

but it only provides a solution for checking hashes, and uses a different method which is not really what I'm aiming for here.

As I said, doing basically the same thing (same file name, code, file size) in another directory works fine.

The error is as follows:

---------------------------------------------------------------------------
OSError                                   Traceback (most recent call last)
~\AppData\Local\Temp\ipykernel_19332\1902527957.py in <module>
----> 1 data=wf_loader('adb', state=2)
      2 #wf_loader('adb', state=1)
      3 #wf_loader('diab', state=1)
      4 #wf_loader('diab', state=2)

~\AppData\Local\Temp\ipykernel_19332\168813414.py in wf_loader(representation, state, save)
     22     with open(file) as di_data:
     23         print(di_data)
---> 24         lines = di_data.readlines()
     25 
     26     xlims, ylims, x_gridpoints, y_gridpoints = get_data_shape_fromlog()

OSError: [Errno 22] Invalid argument

And the part of the function 'wf_loader' that is not working is below, you can safely ignore the 'state' and 'save' arguments as they are used later in the function and probably not relevant.

 def wf_loader(representation='adb', state=2, save=True):
    '''
    Returns a numpy array for the wavefunction density progressing in time
    
    representation: 'adb' opens the adiabatic wf, 'diab opens the diabatic wf', default adb
    
    state: which state's wavefunction to look at 1 or 2, default 2
    
    save: saves the numpy array as a binary file for easier loading later
    '''

    cwd = os.getcwd()
    
    if representation == 'adb':
        file = os.path.join(cwd, 'adb2d_x_y')
    elif representation == 'diab':
        file = os.path.join(cwd, 'dens2d_x_y')
    else:
        print('Unkown representation')
        return
        
    #Loads file into python
    with open(file) as di_data:
        print(di_data)
        lines = di_data.readlines()

My file structure is as follows. I am running a jupyter notebook in the same directory as the 'adb2d_x_y' and 'dens2d_x_y' files. I only added the os.getcwd() and os.path.join() parts to see if it would make a difference, but it runs perfectly well (in the aforementioned directory where the code works) just using file = 'adb2d_x_y'.

Also 'adb2d_x_y' and 'dens2d_x_y' do not have file extensions as they were imported from some niche program running on Linux, but can be opened using a text editor.

Any help at all here? I feel like it could be some crazy memory error and I would be in way over my head getting into all that (not that it's not something to learn for another time).