Why do I keep getting a SWIG director method error when I try to apply a measure?

edit

I don't think it occurs on "any measure". This is a logic error, clearly, as indicated by the Optional not initialized.

In this specific example, it's happening here: https://github.com/NREL/openstudio-ex...

Meaning your Space does not have a ThermalZone attached to it...

And you're hitting it on any measure that does use that os_lib_hvac.rb's createPrimaryAirLoops function.

Unfortunately, the function is wrong (openstudio-extension-gem 0.7.0 and 0.7.1 are affected at least, but that function was removed for the forthcoming release...):

    if space.thermalZone
      thermal_zone = space.thermalZone.get

Should actually be

    if space.thermalZone.is_initialized   # alternative: !space.thermalZone.empty?
      thermal_zone = space.thermalZone.get

Anyways: to work around your issue, please assign a ThermalZone to all of your Spaces. A Space must have a thermal zone in order to be simulated by E+.