ERROR 10009: HostID mismatch Sonja Mars August 14, 2020 15:53 Updated Follow We discuss this error and its resolution in detail here. Related articles What system changes can invalidate a license file? How do I transfer my free academic or free trial license to a different computer? ERROR 10009: License is for 8 cores, machine has xx How does Gurobi count cores? How do I resolve an "ERROR 10009: License is for 8 cores, machine has XX"?