Error regarding saving of simulation file


I am getting this error frequently these days while I try to save my simulation file, especially when I am using the human model "DUKE". If I close the simulation file after getting this error, the simulation data and analysis result automatically gets deleted. Does anyone know the reason and suggestion on how to solve this problem? Refer to the attached image for the error (last line - free store overflow).

P.S - Simulations are mostly related to EM-FDTD MULTIPORT.

Thank you