The errors
Unable to open Gurobi license file 'C:\gurobi\gurobi.lic'
Unable to open Gurobi license file '/Library/gurobi1201/gurobi.lic
are most likely caused by Gurobi environment variables that are not set up correctly.
Please make sure that the system environment variable GRB_LICENSE_FILE points to a valid Gurobi license. To check the value of the environment variable, you can run echo $GRB_LICENSE_FILE (for Windows echo %GRB_LICENSE_FILE%).
Note: The system environment variable GRB_LICENSE_FILE must point to the exact location of the file. For example, if the license file gurobi.lic is in the directory D:\work, then GRB_LICENSE_FILE needs to be set as D:\work\gurobi.lic.
Other causes may be that:
- You don't have permission to read the license file.
- The license file has a hidden extension such as .txt or .rtf.
Further information