“biaxialSmooth.py” is not responding(FEMxDEM example)

My operating system version is Ubuntu 20.04.5. My yade is installed from source code and my esys.Escript is installed with anaconda3. I am trying to simulate a FEMxDEM example [1], which baisc theory and introduction is [2]. My code is following:

(terminal is under this directory: /home/ltt/My yade/trunk/examples/FEMxDEM)
$ export PATH=/usr/bin:$PATH
$ export PYTHONPATH="/home/ltt/anaconda3/envs/esys-Escript:../../py/FEMxDEM"
$ export LD_LIBRARY_PATH="/home/ltt/anaconda3/envs/esys-Escript/lib:/home/ltt/'My yade'/insatll/lib"
$ ln -s '/home/ltt/My yade/install/bin/yade-2022-08-26.git-d6517c7' ../../py/FEMxDEM/yadeimport.py
$ '/home/ltt/My yade/install/bin/yade-2022-08-26.git-d6517c7' ./biaxialSmooth.py

Then, the codes are shown:

Welcome to Yade 2022-08-26.git-d6517c7
Using python version: 3.8.10 (default, Jun 22 2022, 20:18:18)
[GCC 9.4.0]
TCP python prompt on localhost:9000, auth cookie `keacuy'
XMLRPC info provider on http://localhost:21000
Running script ./biaxialSmooth.py
=======================================================================
For better performance compile python-escript with direct solver method
=======================================================================
Press Enter to continue...

But this code didn't change for a long time. And the contorller window is stuck. When I try to click some button in this window, It shows "“biaxialSmooth.py” is not responding". I only can click "Force Quit" to kill is process. So I want to ask if my code is right and how to solve this problem?

[1]https://gitlab.com/yade-dev/trunk/-/blob/master/examples/FEMxDEM/biaxialSmooth.py
[2]https://yade-dem.org/doc/FEMxDEM.html