Occasionally I've seen this script access a member of FFX, but it is nil at that point. Line 942:
Code:
FFX, ret = GetFocusedFX(true)
if ret == 1 then
track = GetTrack(FFX.trn)
end
Seems GetFocusedFX() can return nil, 1, which causes this. Also I think there's a typo relating to 'local tr' in the GetTrack() function