OSError: failed to open clipboard

[slevin48]

I'm successfully starting the predict-server.py and playing the Play.lua script in the Lua console on the tt/cm track.
It works for a few seconds (2-3s), we can even see the steering angle evolving from left to right.
But suddenly the server display the following error message:

----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 61375)
Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\socketserver.py", line 316, in _handle_request_noblock
    self.process_request(request, client_address)        
  File "C:\ProgramData\Anaconda3\lib\socketserver.py", line 347, in process_request
    self.finish_request(request, client_address)
  File "C:\ProgramData\Anaconda3\lib\socketserver.py", line 360, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "C:\ProgramData\Anaconda3\lib\socketserver.py", line 720, in __init__
    self.handle()
  File "d:/devel/NeuralKart/predict-server.py", line 38, 
in handle
    im = ImageGrab.grabclipboard()
  File "d:\devel\NeuralKart\env\lib\site-packages\PIL\ImageGrab.py", line 96, in grabclipboard
    fmt, data = Image.core.grabclipboard_win32()
OSError: failed to open clipboard
----------------------------------------