hello experts,
I have faced an error when doing AcuSolve tutorial Acu-T-5403 DCFSI.
I have completely followed the tutorial step by step.
The AcuSolve and OptiStruct solver started and coupled together.
However, after a few time steps, the acuTail displayed below error:

Did anyone face this issue before?
What is the reason and is there any solution for this?
Thanks in advance!