For Windows
Please add the path of glpsol.ext to your Environment variables.
1. Open the Control Panel
2. Click System
3. Click Advanced system setting
4. Open Environment variables
5. Edit Path
6. Add variable value ";the path where glpsol.exe locate" (e.g. ;D:\glpk-4.45\w64)
, set the glpsol executable for your version of Windows into the PATH environment variable.
For Linux or Mac
GLPK
Follow documents to install.