Guilin Sun
Ansys Employee
It might be due to MPI issue ( Failed to post close command error 1726 ). Do you use Microsoft PML? please change to Inter MPI, Or MPICH2:

I am using remote license. If your license is in local computer, you can choose "local computer". Or you can try different MPI that is good for you.

If simulation worked fine before, you may need to restart your computer; download microsoft updates; or reinstall Lumerical products.