Without a valid GAMS license the system will operate as a free demo system with these limitations:

1. Model limits:
   • Number of constraints and variables: 300
   • Number of nonzero elements: 2000 (of which 1000 nonlinear)
   • Number of discrete variables: 50 (including semi continuous, semi integer and member of SOS-Sets)
2. Global solver limits:
   • Number of constraints and variables: 10

The GAMS log will indicate that your system runs in demo mode:

GAMS Rev 227  Copyright (C) 1987-2008 GAMS Development. All rights reserved
Licensee: GAMS Development Corporation, Washington, DC   G871201/0000CA-ANY
          Free Demo,  202-342-0180,  sales@gams.com,  www.gams.com   DC0000
--- Starting compilation
...

GAMS will terminate with a licensing error if you hit one of the limits above.