Assuming that you are using the Legacy plugin, you’ll have to make sure you have Ladybug 0.0.69 and Honeybee 0.0.66 [Legacy Plugins] installed from Food4Rhino. Then, you’ll have to make sure OpenStudio 3.0 is installed in it’s default location in the C:\ drive. Lastly, you’ll have to follow the instructions here to get OpenStudio 3.0 to play nicely with legacy honeybee: