diff --git a/lerobot/scripts/server/buffer.py b/lerobot/scripts/server/buffer.py
index c8f85372..8947f6d9 100644
--- a/lerobot/scripts/server/buffer.py
+++ b/lerobot/scripts/server/buffer.py
@@ -15,7 +15,6 @@
 # limitations under the License.
 import functools
 import io
-import os
 import pickle
 from typing import Any, Callable, Optional, Sequence, TypedDict
 
@@ -388,8 +387,8 @@ class ReplayBuffer:
         Yields:
             BatchTransition: Prefetched batch transitions
         """
-        import threading
         import queue
+        import threading
 
         # Use thread-safe queue
         data_queue = queue.Queue(maxsize=queue_size)
diff --git a/lerobot/scripts/server/maniskill_manipulator.py b/lerobot/scripts/server/maniskill_manipulator.py
index b5c181c1..03a7ec10 100644
--- a/lerobot/scripts/server/maniskill_manipulator.py
+++ b/lerobot/scripts/server/maniskill_manipulator.py
@@ -1,5 +1,3 @@
-import logging
-import time
 from typing import Any
 
 import einops
@@ -10,10 +8,6 @@ from mani_skill.utils.wrappers.record import RecordEpisode
 from mani_skill.vector.wrappers.gymnasium import ManiSkillVectorEnv
 
 from lerobot.common.envs.configs import ManiskillEnvConfig
-from lerobot.configs import parser
-from lerobot.configs.train import TrainPipelineConfig
-from lerobot.common.policies.sac.configuration_sac import SACConfig
-from lerobot.common.policies.sac.modeling_sac import SACPolicy
 
 
 def preprocess_maniskill_observation(