Fatal License Error: Unable to checkout a license. (ModelSim-Altera 6.1d) - Fatal License Error: Unable to checkout a license. (ModelSim-Altera 6.1d) Description You may see the following error message when you run the ModelSim® -Altera® software version 6.1d if you have a floating license and the mgcld license daemon is too old: Unable to checkout a license. Make sure your license file environment variables are set correctly and then run 'lmutil lmdiag' to diagnose the problem. Modelsim-Altera uses the following environment variables to check the licenses (listed in the order of preference) 1. MGLS_LICENSE_FILE 2. LM_LICENSE_FILE. The mgcld daemon included with the Quartus ® II software version 6.0 in < Quartus II installation directory >\ win is version 8.2, which is too old. The correct daemon is provided beginning with the Quartus II software version 6.1. To use the ModelSim-Altera software version 6.1d, you should use version 9.5 of the mgcld daemon included with the ModelSim-Altera software version 6.1d. The mgcld daemon is in < ModelSim-Altera installation directory \ win32aloem . If you need the mgcld daemon for a different operating system, download the appropriate file at the License Daemon Downloads web page. Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['novalue'] novalue novalue ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']