Occasional `ValueError: need at least one array to concatenate` while recording

[Saad-Mufti]

While recording EEG data, sometimes I get the following issue:

Traceback (most recent call last):
  File "c:\Users\...\muse-send.py", line 55, in <module>
    muselsl.record(t_step, file_name)
  File "C:\Users\...\AppData\Roaming\Python\Python39\site-packages\muselsl\record.py", line 93, in record
    _save(
  File "C:\Users\...\AppData\Roaming\Python\Python39\site-packages\muselsl\record.py", line 137, in _save
    res = np.concatenate(res, axis=0)
  File "<__array_function__ internals>", line 5, in concatenate
ValueError: need at least one array to concatenate

For reference, I am using Python 3.9.5, Windows 11, and muselsl=2.2.1.