Complex model of an FSI simulation

Hello everyone,
I am currently creating a complex model of an FSI simulation when suddenly I stopped due to an error message. Below is the pop up message that occurred as I was working.
ERROR #002100061 has occurred in subroutine SERVE_CLIENTS.
Message:
The connection between this CFX process and an external process has died unexpectedly. The following error was received: External process : ANSYS Error experienced : Read
I was hoping that you could help me know the problem better by telling me how this error happened and why.
Thank you.
