diff --git a/torchrl/collectors/_runner.py b/torchrl/collectors/_runner.py
index f2db7b32e8e..c43b88060cf 100644
--- a/torchrl/collectors/_runner.py
+++ b/torchrl/collectors/_runner.py
@@ -487,7 +487,7 @@ def cast_tensor(x, MPS_ERROR=MPS_ERROR):
                             if x.device.type in ("cpu",):
                                 x.share_memory_()
                             if x.device.type in ("mps",):
-                                RuntimeError(MPS_ERROR)
+                                raise RuntimeError(MPS_ERROR)
 
                         collected_tensordict.apply(cast_tensor, filter_empty=True)
                 data = (collected_tensordict, idx)
diff --git a/torchrl/collectors/distributed/ray.py b/torchrl/collectors/distributed/ray.py
index 2f8930207f6..dc2df7eb3e1 100644
--- a/torchrl/collectors/distributed/ray.py
+++ b/torchrl/collectors/distributed/ray.py
@@ -1010,7 +1010,7 @@ def _async_iterator(self) -> Iterator[TensorDictBase]:
 
             if self.update_after_each_batch or self.max_weight_update_interval > -1:
                 torchrl_logger.debug(f"Updating weights on worker {collector_index}")
-                self.update_policy_weights_(worker_ids=collector_index + 1)
+                self.update_policy_weights_(worker_ids=collector_index)
 
             # Schedule a new collection task
             future = collector.next.remote()
diff --git a/torchrl/data/tensor_specs.py b/torchrl/data/tensor_specs.py
index 8b67103c416..310b1ecd44c 100644
--- a/torchrl/data/tensor_specs.py
+++ b/torchrl/data/tensor_specs.py
@@ -1229,9 +1229,7 @@ def __torch_function__(
         if func not in cls.SPEC_HANDLED_FUNCTIONS or not all(
             issubclass(t, (TensorSpec,)) for t in types
         ):
-            return NotImplementedError(
-                f"func {func} for spec {cls} with handles {cls.SPEC_HANDLED_FUNCTIONS}"
-            )
+            return NotImplemented
         return cls.SPEC_HANDLED_FUNCTIONS[func](*args, **kwargs)
 
     def unbind(self, dim: int = 0):