Lito
Ansys Employee

@Chengkuan Gao,

To resolve this issue. Add the Lumerical install path into your PATH.
>>Setting environment variable in Linux – Ansys Optics 

Otherwise, run “cmlc” directly from the Terminal and not from the Launcher. 
>>Running the Ansys Lumerical CAD/IDE – Ansys Optics 

Check out the CML compiler documentation for information on how to use this tool. Requires CMLC license and access to the Ansys Optics. 
>>Access to the CML compiler documentation – Ansys Optics 
>>CML Compiler product reference manual – Ansys Optics