if you look here:

https://github.com/mne-tools/mne-python/blob/master/mne/fiff/tag.py#L418

eeg_loc can be 1d and the lines above will crash. I understand that ch['eeg_loc'][:, 1] is the
extent of the electrode? Can we have a value by default to have consistently a 2d array
for eeg_loc?

@mshamalainen any hint to share on this?