0. Runtime error (MissingMemberException): 'IB_HVACSystem' object has no attribute 'display_name'

Hi All,

I am tiring to learn IB by reproduce the you tube example " Build a HVAC system in Grasshopper (2) VRF + DOAS" with the latest versions of LBT. I get the subject error message and cant find a way to solve it. Any help will be appreciated.
thx in advance