The cause of the issue is the menu item Publications with URL –
Your site should function fine if you remove that URL. The theme is trying to treat this as an internal URL because of presence of #group but failing since it is not really a valid internal URL. Do you have the option of removing that URL ?
If you put the same in the dropdown menu which is shown on hover, you will have no issues, BTW. Only if it resides on the top level menu, it could lead to issues. I would suggest you make it a menu with single dropdown item which is seen on hover and which points to the URL above. Thanks.