@shakeelsindhu@Naf.H Is this issue occurring only when opening a specific USD file? Could you please try opening some of the Isaac Sim Assets to see if the problem persists?
The URDF import simply crashes IsaacSim4.5 while the USD files which were fine previously now some of them are loaded with multiple errors (like ZED Camera missing, Assets errors, so and so).
I’ve reinstalled 4.2 to see if I am still able to use IsaacSim.
I will share further logs for inspection and your take-on on them.