Recently a NEURON user reported that trying to bring up a PointProcessManager instead caused a window to appear that reported
No accessed section: Can't start a PointProcessManager
Under recent versions of NEURON (7.1 for sure) this means that no sections have been created. Type the command
at the oc> prompt and NEURON will print out the names of all sections that exist. If there are no sections, revise your code so that it creates sections.