VMD can't read mmCif files generated by OpenMM

[Rob-Welch]

Upon trying to read an mmCif format file written by openmm, VMD shows this useless error message:

vmd > pdbxplugin) Could not get atom number
pdbxplugin) error opening file.
ERROR) Could not read file filename.cif

I still consider this an upstream problem, and as far as I can tell the file written by OMM is well-formed. Unfortunately, right now the VMD bug tracker is just returning internal server errors.