Traceback (most recent call last):
  File "electrum/plugin.py", line 362, in wrapper
  File "electrum/plugin.py", line 355, in run_in_hwd_thread
  File "concurrent/futures/_base.py", line 446, in result
  File "concurrent/futures/_base.py", line 391, in __get_result
  File "concurrent/futures/thread.py", line 58, in run
  File "/Users/florianfleischmann/Desktop/Electrum.app/Contents/MacOS/electrum/plugins/safe_t/clientbase.py", line 164, in cancel
    self.transport.write(self.proto.Cancel())
  File "safetlib/transport_hid.py", line 151, in write
  File "safetlib/protocol_v1.py", line 48, in write
  File "safetlib/transport_hid.py", line 159, in write_chunk
  File "hid.pyx", line 84, in hid.device.write
ValueError: not open