Closing this thread based on the findings here.
The carb.datastore.plugin / omni.datastore lock error is non-fatal. When a process cannot acquire the shared cache lock, it falls back to local PhysX cooking and the simulation continues normally. As @yioutpi confirmed in post #11, programs run fine despite the error.
Summary for anyone landing here:
- The lock limit is 64 in Isaac Sim 4.x and 256 in 5.x.
- If you exceed the limit, you’ll see the error in logs but your simulation will still work.
- To suppress the error, launch with
--/physics/cooking/ujitsoCollisionCooking=false(disables the shared PhysX cooking cache entirely). - Making the lock limit user-configurable has been noted as a feature request internally.
A related thread for Isaac Sim 5.1.0 is tracked here: Omni.datastore error.