Hi,

I executed 'color zone #2 near #1 distance 5 sharpEdges true' to colour a map I loaded, followed by "volume splitbyzone #2', but repeatedly would get an error that the volume specified is not coloured by zone. Eventually after trying multiple times, it worked, however the log outputted the following:

Traceback (most recent call last):
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/core/triggerset.py", line 130, in invoke
    return self._func(self._name, data)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/map/volume.py", line 3557, in _update_drawings
    v.update_drawings()
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/map/volume.py", line 701, in update_drawings
    self._update_surfaces()
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/map/volume.py", line 724, in _update_surfaces
    s.update_surface(ro)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/map/volume.py", line 1953, in update_surface
    va, na, ta, hidden_edges = self._calculate_contour_surface(matrix, level, rendering_options)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/map/volume.py", line 2048, in _calculate_contour_surface
    rendering_options, level)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/map/volume.py", line 2071, in _adjust_surface_geometry
    varray, tarray, narray = subdivide_triangles(varray, tarray, narray)
ValueError: not enough values to unpack (expected 3, got 2)
Error processing trigger "graphics update": not enough values to unpack (expected 3, got 2):
ValueError: not enough values to unpack (expected 3, got 2)
File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/map/volume.py", line 2071, in _adjust_surface_geometry
varray, tarray, narray = subdivide_triangles(varray, tarray, narray)

I also get the following when using the color zone command, even though color zone works (most of the times, sometimes it fails)

Traceback (most recent call last):
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/cmd_line/tool.py", line 254, in execute
    cmd.run(cmd_text)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/core/commands/cli.py", line 2641, in run
    result = ci.function(session, **kw_args)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/std_commands/color.py", line 1248, in color_zone
    color_zone(s, spoints, colors, distance, sharp_edges = sharp_edges, auto_update = update)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/surface/colorzone.py", line 14, in color_zone
    zc.set_vertex_colors()
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/surface/colorzone.py", line 84, in set_vertex_colors
    replace = True)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/surface/colorzone.py", line 123, in color_zone_sharp_edges
    ec = _edge_cuts(varray, tarray, i1, n1, points, colors, distance)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/surface/colorzone.py", line 147, in _edge_cuts
    f = _edge_cut_position(varray, v1, v2, p1, p2, points, colors, distance)
  File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/surface/colorzone.py", line 181, in _edge_cut_position
    raise ValueError('Cut fraction %.5g is out of range (0,1)' % f)
ValueError: Cut fraction 1.8061 is out of range (0,1)
ValueError: Cut fraction 1.8061 is out of range (0,1)
File "/usr/lib/ucsf-chimerax-daily/lib/python3.7/site-packages/chimerax/surface/colorzone.py", line 181, in _edge_cut_position
raise ValueError('Cut fraction %.5g is out of range (0,1)' % f)