Particle Detection Fails

[evamvid]

Running on Arch Linux, Particle Detection fails with the following error:

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python3.9/tkinter/__init__.py", line 1892, in __call__
    return self.func(*args)
  File "/home/user/coffeegrindsize/coffeegrindsize.py", line 592, in <lambda>
    psd_button = Button(toolbar, text="Launch Particle Detection", command=lambda: self.launch_psd(None),highlightbackground=toolbar_bg)
  File "/home/user/coffeegrindsize/coffeegrindsize.py", line 2341, in launch_psd
    self.cluster_data.append(clusteri_data)
AttributeError: 'NoneType' object has no attribute 'append'