The error ERROR 10009: HostID mismatch indicates that the license key was generated for a machine with a different HostID. If the license previously worked on the machine, then something in the machine configuration has changed. These changes can include:
- For Windows systems: modifying the primary disk volume ID, which can be caused by formatting or replacing the boot drive
- For Linux and macOS: modifying the primary network adapter; this may occur when attaching and detaching from some docking stations
- For named-user licenses: running under a different username
- For WSL2: the MAC address changes upon rebooting. Try using WSL1.
Note: When running Gurobi Optimizer on a virtual machine, some of these identifiers may change if you "copy" the virtual machine. To migrate a virtual machine to a new host, select the option in your virtualization system to "move" the virtual machine rather than "copying" or "cloning" it.