Hi,
I have a question regarding vaa3d that I would like to address to here. I'm trying to automatically trace the cell body of neurons in order to measure the soma size. I acquired images of GFP positive neurons using a confocal microscope. However, when I run the plugin Vaa3d-Neuron2-APP1 the program gives me the following error notification: the plugin fails to run (also see screenshot). I also attached the tiff file of the neuron I'd like to measure.

What could I do to solve this, or what would be another well suited way to measure soma size in 3D? What is in general the best way to measure soma size of neurons? I am not interested in tracing any neurites. 

Thank you very much in advance. 

Best,
Job