FDTD simulation did not complete successfully: status 0.0 error during topology optimization 3DFDTD

aaltindag20aaltindag20 Member Posts: 4


I get the FDTD simulation did not complete successfully: status 0.0 error when run the Y-splitter topology optimization example for 3D FDTD. The optimization starts, but I get this error after a few iterations. How can I fix this problem? Could you help me to solve this problem? Thank you.


  • kjohnsonkjohnson Ansys Employee Posts: 18


    First, what software release are you using? And have you made changes to the example, or are you running the example files exactly as they are?

    This error indicates one of the forward or adjoint simulations didn't complete successfully. This could be due to running out of memory, losing access to the license server, etc. The cause of the crash should be at the bottom of the log file for the simulation. The log file should be in the "opts" folder, with a name similar to "forward_0_p0". Can you let me know what it says?

  • aaltindag20aaltindag20 Member Posts: 4

    Hello @kjohnson,

    I am using Lumerical 2021 R1. I have changed the example files, I set mesh accuracy to 3, and autoshutoff to 1e-4. I am also running 90-10 Y-splitter.

    The log file says:

    "Ansys Lumerical 2021 R1 FDTD Solver Version 8.25.2525 (Windows 64bit)

     expires (month/day/year): 4/28/2021

    using config file: C:/Users/aaltindag20/AppData/Roaming/Lumerical/License.ini

    license host:

    current time: Tue Feb 16 13:14:45 2021

    Running on host: DESKTOP-O0U637V

    host available memory (GB): 184.180224".

  • aaltindag20aaltindag20 Member Posts: 4

    Hello @kjohnson ,

    I gave incomplete information about the log file in the previous message, sorry for this. I add the log file, it says the simulation completes successfully. However, as I mentioned before, the optimization stops after a few iterations. Thanks for your help.

  • kjohnsonkjohnson Ansys Employee Posts: 18

    Unfortunately Ansys employees are not permitted to download files from the Learning Forum, so I can't download your log file. But if the log file doesn't mention an error and says that the simulation was successful then that should be enough information. This log file should be from the final simulation before the error is encountered. If the log file says the simulation completed successfully but Python returned a simulation error, it's possible the simulation didn't start at all before it encountered the error. This might be caused by losing connection to your license server. You mentioned that a few iterations were successful, how long did it take to run these iterations before the error was encountered?

    The final forward/adjoint simulation files should be saved in the opts folder along with the log file. Are you able to open these files and run them individually?

  • aaltindag20aaltindag20 Member Posts: 4

    Hello @kjohnson,

    The log file says that the simulation completed successfully. It takes 5-6 minutes to run each iteration. And, I am able to open and run forward and adjoint simulation files. Thanks.

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