The running of isaac omniverse model stopped

i am running a python script to control an object with multiple joints.
this scripts is written in jupyter notebook.
here is the part of the script to control the joints by a loop to change the initial values of zero .

after running the script , the screen of isaac omnivers stopped and show a message of quit or wait . as bellow :

Screenshot 2023-11-25 002059

my pc has a NVIDIA GeForce RTX 3060
as bellow :

here is the terminal during running my script:

I have 4 joints to control , my code was working previously when entering the 4 joints. now i want to control only two joints : Base_link and fork_joint.
the sequnce shall be as bellow :
try to move the fork from 0 till 50 by a step of 10 ,
after reach 50 , start moving the base from 0 to 100 ,by a step of 1
then stop the movement.

any help please to understand my issue and the reason to get such error.