All of our themes (except for Rubric) use a Site Header module for the header. If you are instead seeing a Menu module in the Website Header global then you have run into a strange bug of HubSpot's. Sometimes after downloading a theme the HubSpot system will replace the contents in the global header with its own default modules.
In most cases you should be able to resolve this by opening the Website Header global and going to View > Version History.
Tip: For more information on accessing the Website Header global refer to the knowledgebase article How To Edit Your Header and Footer.
Select the very last version in the listing (names, dates, and times will be different than what is in this screenshot).
And then click the orange Restore version button in the top right corner.
