It has come to our attention that a new version (0.7) of the HVAC Python module has been released today and is incompatible with our genvid-toolbox.
To workaround this you will need to run
pip install 'hvac<0.7' at the command prompt after running
install-toolbox.py to downgrade to a working version of HVAC.
Apologies for the inconvenience, this issue will be fixed in an upcoming release of the SDK.