From Ancestry German and Jewish (Ashkenazic): from Middle High German herre, German Herr ‘master’, ‘lord’; a nickname for someone who gave himself airs and behaved in a lordly manner, or an occupational name for someone in the service of the lord of the manor.
In the case of The Reverend Bishop Hans Haas Herr, his ancestor was named Johannes and he was the "Lord of Bilried", which evidently evolved into "Johannes Herr". -W