diff --git a/src/llmtuner/extras/callbacks.py b/src/llmtuner/extras/callbacks.py
index 69c45e17..6c082f92 100644
--- a/src/llmtuner/extras/callbacks.py
+++ b/src/llmtuner/extras/callbacks.py
@@ -46,7 +46,7 @@ class LogCallback(TrainerCallback):
         r"""
         Event called after logging the last logs.
         """
-        if "current_steps" not in state.log_history[-1]:
+        if "step" not in state.log_history[-1]:
             return
         cur_time = time.time()
         cur_steps = state.log_history[-1].get("step")
diff --git a/src/llmtuner/tuner/core/loader.py b/src/llmtuner/tuner/core/loader.py
index a6b1c0f5..d80afa70 100644
--- a/src/llmtuner/tuner/core/loader.py
+++ b/src/llmtuner/tuner/core/loader.py
@@ -10,7 +10,7 @@ from transformers import (
 )
 from transformers.utils import check_min_version
 from transformers.utils.versions import require_version
-from transformers.modeling_utils import PreTrainedModel
+from transformers.modeling_utils import PretrainedConfig, PreTrainedModel
 from transformers.tokenization_utils import PreTrainedTokenizer
 from trl import AutoModelForCausalLMWithValueHead
 
@@ -113,11 +113,11 @@ def load_model_and_tokenizer(
     )
 
     # Register auto class to save the custom code files.
-    if hasattr(config, "auto_map") and "AutoConfig" in config.auto_map:
+    if hasattr(config, "auto_map") and "AutoConfig" in config.auto_map and isinstance(config, PretrainedConfig):
         config.__class__.register_for_auto_class()
-    if hasattr(config, "auto_map") and "AutoTokenizer" in config.auto_map:
+    if hasattr(config, "auto_map") and "AutoTokenizer" in config.auto_map and isinstance(tokenizer, PreTrainedTokenizer):
         tokenizer.__class__.register_for_auto_class()
-    if hasattr(config, "auto_map") and "AutoModelForCausalLM" in config.auto_map:
+    if hasattr(config, "auto_map") and "AutoModelForCausalLM" in config.auto_map and isinstance(model, PreTrainedModel):
         model.__class__.register_for_auto_class()
 
     # Initialize adapters
diff --git a/src/llmtuner/tuner/core/trainer.py b/src/llmtuner/tuner/core/trainer.py
index 8b057ff3..a54d93cb 100644
--- a/src/llmtuner/tuner/core/trainer.py
+++ b/src/llmtuner/tuner/core/trainer.py
@@ -23,6 +23,9 @@ class PeftTrainer(Seq2SeqTrainer):
     def __init__(self, finetuning_args: FinetuningArguments, **kwargs):
         super().__init__(**kwargs)
         self.finetuning_args = finetuning_args
+        self._remove_log()
+
+    def _remove_log(self):
         if self.is_world_process_zero() and os.path.exists(os.path.join(self.args.output_dir, "trainer_log.jsonl")):
             logger.warning("Previous log file in this folder will be deleted.")
             os.remove(os.path.join(self.args.output_dir, "trainer_log.jsonl"))
diff --git a/src/llmtuner/tuner/ppo/trainer.py b/src/llmtuner/tuner/ppo/trainer.py
index 8612ecc2..a786e1fe 100644
--- a/src/llmtuner/tuner/ppo/trainer.py
+++ b/src/llmtuner/tuner/ppo/trainer.py
@@ -40,6 +40,7 @@ class PPOPeftTrainer(PPOTrainer, PeftTrainer):
         self.state = TrainerState()
         self.control = TrainerControl()
         self.data_collator = self.accelerator.prepare(kwargs["data_collator"]) # override the data collator of PPOTrainer
+        self._remove_log()
 
     def ppo_train(self, max_target_length: int) -> None:
         r"""